ATI Drivers constantly crashing and causing BSODs

Hi, here are some of my system specs:
Video card: Sapphire ATI Radeon 5850 Xtreme
Mobo: Gigabyte GA-HA65M-UD3H-B3
CPU: Intel Core i5-2500
RAM: 8 GB (4x2) DDR3 1333Mhz
Power supply: Seasonic M12II-620Bronze (620 Watts)
Windows 7 Ultimate 64 bit, build 7601: SP1

My PC is only a few months old, but my video card is already giving me hell.
Everything worked just fine (or at least it seemed so), until my PC suddenly froze and crashed after a few seconds.
Now, whenever I boot up, I can't get through the windows splash loading screen. When it finishes loading, I either get a black screen and nothing happens (no cursor shows up and there are no booting sounds), or I get a BSOD.
The only way I can boot is by disabling my video driver using safe mode.
I tried installing other versions of the ATI driver, but the error repeats itself in 2 different ways:
1. If I only install the driver without the ATI Catalyst Control Center, Windows actually boots just fine, but after a few minutes of use, it freezes and crashes.
2. When I install the whole Catalyst package, I get the same as I described before - when booting, either a BSOD or a blank black screen appear after the Windows loading splash screen.


Here are the analyses of 2 of the minidumps created:

Microsoft (R) Windows Debugger Version 6.12.0002.633 AMD64
Copyright (c) Microsoft Corporation. All rights reserved.


Loading Dump File [C:\Windows\Minidump\100311-23868-01.dmp]
Mini Kernel Dump File: Only registers and stack trace are available

Symbol search path is: SRV*c:\websymbols*http://msdl.microsoft.com/download/symbols
Executable search path is:
Windows 7 Kernel Version 7601 (Service Pack 1) MP (4 procs) Free x64
Product: WinNt, suite: TerminalServer SingleUserTS
Built by: 7601.17640.amd64fre.win7sp1_gdr.110622-1506
Machine Name:
Kernel base = 0xfffff800`03a09000 PsLoadedModuleList = 0xfffff800`03c4e670
Debug session time: Mon Oct 3 14:54:08.403 2011 (UTC + 2:00)
System Uptime: 0 days 0:00:42.230
Loading Kernel Symbols
...............................................................
................................................................
............................................
Loading User Symbols
Loading unloaded module list
....
*******************************************************************************
* *
* Bugcheck Analysis *
* *
*******************************************************************************

Use !analyze -v to get detailed debugging information.

BugCheck 116, {fffffa800a13f390, fffff880045bd024, 0, 2}

Unable to load image \SystemRoot\system32\DRIVERS\atikmpag.sys, Win32 error 0n2
*** WARNING: Unable to verify timestamp for atikmpag.sys
*** ERROR: Module load completed but symbols could not be loaded for atikmpag.sys
Probably caused by : atikmpag.sys ( atikmpag+6024 )

Followup: MachineOwner
---------

2: kd> !analyze -v
*******************************************************************************
* *
* Bugcheck Analysis *
* *
*******************************************************************************

VIDEO_TDR_FAILURE (116)
Attempt to reset the display driver and recover from timeout failed.
Arguments:
Arg1: fffffa800a13f390, Optional pointer to internal TDR recovery context (TDR_RECOVERY_CONTEXT).
Arg2: fffff880045bd024, The pointer into responsible device driver module (e.g. owner tag).
Arg3: 0000000000000000, Optional error code (NTSTATUS) of the last failed operation.
Arg4: 0000000000000002, Optional internal context dependent data.

Debugging Details:
------------------


FAULTING_IP:
atikmpag+6024
fffff880`045bd024 4883ec28 sub rsp,28h

DEFAULT_BUCKET_ID: GRAPHICS_DRIVER_TDR_FAULT

CUSTOMER_CRASH_COUNT: 1

BUGCHECK_STR: 0x116

PROCESS_NAME: System

CURRENT_IRQL: 0

STACK_TEXT:
fffff880`06383888 fffff880`050d8000 : 00000000`00000116 fffffa80`0a13f390 fffff880`045bd024 00000000`00000000 : nt!KeBugCheckEx
fffff880`06383890 fffff880`050d7d0a : fffff880`045bd024 fffffa80`0a13f390 fffffa80`092b8d50 fffffa80`0925f410 : dxgkrnl!TdrBugcheckOnTimeout+0xec
fffff880`063838d0 fffff880`0517ef07 : fffffa80`0a13f390 00000000`00000000 fffffa80`092b8d50 fffffa80`0925f410 : dxgkrnl!TdrIsRecoveryRequired+0x1a2
fffff880`06383900 fffff880`051a8b75 : 00000000`ffffffff 00000000`000009b9 00000000`00000000 00000000`00000002 : dxgmms1!VidSchiReportHwHang+0x40b
fffff880`063839e0 fffff880`051a72bb : 00000000`00000102 00000000`00000000 00000000`000009b9 00000000`00000000 : dxgmms1!VidSchiCheckHwProgress+0x71
fffff880`06383a10 fffff880`0517a2c6 : ffffffff`ff676980 fffffa80`0925f410 00000000`00000000 00000000`00000000 : dxgmms1!VidSchiWaitForSchedulerEvents+0x1fb
fffff880`06383ab0 fffff880`051a6e7a : 00000000`00000000 fffffa80`09021930 00000000`00000080 fffffa80`0925f410 : dxgmms1!VidSchiScheduleCommandToRun+0x1da
fffff880`06383bc0 fffff800`03d20fee : 00000000`fffffc32 fffffa80`08f8cb60 fffffa80`066eeae0 fffffa80`08f8cb60 : dxgmms1!VidSchiWorkerThread+0xba
fffff880`06383c00 fffff800`03a775e6 : fffff800`03bfbe80 fffffa80`08f8cb60 fffff800`03c09cc0 00000000`00000000 : nt!PspSystemThreadStartup+0x5a
fffff880`06383c40 00000000`00000000 : 00000000`00000000 00000000`00000000 00000000`00000000 00000000`00000000 : nt!KxStartSystemThread+0x16


STACK_COMMAND: .bugcheck ; kb

FOLLOWUP_IP:
atikmpag+6024
fffff880`045bd024 4883ec28 sub rsp,28h

SYMBOL_NAME: atikmpag+6024

FOLLOWUP_NAME: MachineOwner

MODULE_NAME: atikmpag

IMAGE_NAME: atikmpag.sys

DEBUG_FLR_IMAGE_TIMESTAMP: 4b68ec4f

FAILURE_BUCKET_ID: X64_0x116_IMAGE_atikmpag.sys

BUCKET_ID: X64_0x116_IMAGE_atikmpag.sys

Followup: MachineOwner
---------

*******************************************************************************
* *
* Bugcheck Analysis *
* *
*******************************************************************************

Use !analyze -v to get detailed debugging information.

BugCheck 1000007E, {ffffffffc0000094, fffff88004b1c5ad, fffff88006dd4b78, fffff88006dd43d0}

Probably caused by : atikmdag.sys ( atikmdag+e45ad )

Followup: MachineOwner
---------

3: kd> !analyze -v
*******************************************************************************
* *
* Bugcheck Analysis *
* *
*******************************************************************************

SYSTEM_THREAD_EXCEPTION_NOT_HANDLED_M (1000007e)
This is a very common bugcheck. Usually the exception address pinpoints
the driver/function that caused the problem. Always note this address
as well as the link date of the driver/image that contains this address.
Some common problems are exception code 0x80000003. This means a hard
coded breakpoint or assertion was hit, but this system was booted
/NODEBUG. This is not supposed to happen as developers should never have
hardcoded breakpoints in retail code, but ...
If this happens, make sure a debugger gets connected, and the
system is booted /DEBUG. This will let us see why this breakpoint is
happening.
Arguments:
Arg1: ffffffffc0000094, The exception code that was not handled
Arg2: fffff88004b1c5ad, The address that the exception occurred at
Arg3: fffff88006dd4b78, Exception Record Address
Arg4: fffff88006dd43d0, Context Record Address

Debugging Details:
------------------


EXCEPTION_CODE: (NTSTATUS) 0xc0000094 - {EXCEPTION} Integer division by zero.

FAULTING_IP:
atikmdag+e45ad
fffff880`04b1c5ad 41f7f0 div eax,r8d

EXCEPTION_RECORD: fffff88006dd4b78 -- (.exr 0xfffff88006dd4b78)
ExceptionAddress: fffff88004b1c5ad (atikmdag+0x00000000000e45ad)
ExceptionCode: c0000094 (Integer divide-by-zero)
ExceptionFlags: 00000000
NumberParameters: 0

CONTEXT: fffff88006dd43d0 -- (.cxr 0xfffff88006dd43d0)
rax=000000000009c400 rbx=fffff88006dd4e00 rcx=000000000009c400
rdx=0000000000000000 rsi=fffffa800909d400 rdi=fffff88004a38000
rip=fffff88004b1c5ad rsp=fffff88006dd4db0 rbp=0000000000000026
r8=0000000000000000 r9=00000000000071f2 r10=fffff88006dd4e00
r11=fffff88004fcf520 r12=0000000000000000 r13=00000000ffffffff
r14=00000000000009dd r15=00000000000009de
iopl=0 nv up ei pl nz na po nc
cs=0010 ss=0000 ds=002b es=002b fs=0053 gs=002b efl=00010206
atikmdag+0xe45ad:
fffff880`04b1c5ad 41f7f0 div eax,r8d
Resetting default scope

CUSTOMER_CRASH_COUNT: 1

DEFAULT_BUCKET_ID: VISTA_DRIVER_FAULT

BUGCHECK_STR: 0x7E

PROCESS_NAME: csrss.exe

CURRENT_IRQL: 0

ERROR_CODE: (NTSTATUS) 0xc0000094 - {EXCEPTION} Integer division by zero.

LAST_CONTROL_TRANSFER: from fffffa800812c786 to fffff88004b1c5ad

STACK_TEXT:
fffff880`06dd4db0 fffffa80`0812c786 : fffff880`04d1ad2a 00000000`00000081 00000000`00017698 fffff880`06dd4e90 : atikmdag+0xe45ad
fffff880`06dd4db8 fffff880`04d1ad2a : 00000000`00000081 00000000`00017698 fffff880`06dd4e90 fffff880`04b1b709 : 0xfffffa80`0812c786
fffff880`06dd4dc0 00000000`00000081 : 00000000`00017698 fffff880`06dd4e90 fffff880`04b1b709 00000000`00000027 : atikmdag+0x2e2d2a
fffff880`06dd4dc8 00000000`00017698 : fffff880`06dd4e90 fffff880`04b1b709 00000000`00000027 00000000`00000000 : 0x81
fffff880`06dd4dd0 fffff880`06dd4e90 : fffff880`04b1b709 00000000`00000027 00000000`00000000 00000013`00000040 : 0x17698
fffff880`06dd4dd8 fffff880`04b1b709 : 00000000`00000027 00000000`00000000 00000013`00000040 00000081`00000002 : 0xfffff880`06dd4e90
fffff880`06dd4de0 00000000`00000027 : 00000000`00000000 00000013`00000040 00000081`00000002 fffff880`06dd4e90 : atikmdag+0xe3709
fffff880`06dd4de8 00000000`00000000 : 00000013`00000040 00000081`00000002 fffff880`06dd4e90 fffffa80`0909d400 : 0x27


FOLLOWUP_IP:
atikmdag+e45ad
fffff880`04b1c5ad 41f7f0 div eax,r8d

SYMBOL_STACK_INDEX: 0

SYMBOL_NAME: atikmdag+e45ad

FOLLOWUP_NAME: MachineOwner

MODULE_NAME: atikmdag

IMAGE_NAME: atikmdag.sys

DEBUG_FLR_IMAGE_TIMESTAMP: 4ddc6c20

STACK_COMMAND: .cxr 0xfffff88006dd43d0 ; kb

FAILURE_BUCKET_ID: X64_0x7E_atikmdag+e45ad

BUCKET_ID: X64_0x7E_atikmdag+e45ad

Followup: MachineOwner
---------

Any clues on what I can do would be extremely appreciated :)