OK I thought the other BSOD might of been a one off... Had another BSOD (BSV points to dxgmms1.sys- nVidia driver, but i dont actually know if that is the cause)
(attached) and have followed your steps.
This is using the latest WHQL Driver for the 580M GTX, 301.42
Overclocking
Only overclocking going on is the CPU going into Turbo Mode (rarely)
Disk checks are done:
Results
C: (OCZ vertex 3 240GB SSD)
Code:
Checking file system on C:
The type of the file system is NTFS.
A disk check has been scheduled.
Windows will now check the disk.
CHKDSK is verifying files (stage 1 of 5)...
212224 file records processed. File verification completed.
292 large file records processed. 0 bad file records processed. 2 EA records processed. 45 reparse records processed. CHKDSK is verifying indexes (stage 2 of 5)...
262336 index entries processed. Index verification completed.
0 unindexed files scanned. 0 unindexed files recovered. CHKDSK is verifying security descriptors (stage 3 of 5)...
212224 file SDs/SIDs processed. Cleaning up 258 unused index entries from index $SII of file 0x9.
Cleaning up 258 unused index entries from index $SDH of file 0x9.
Cleaning up 258 unused security descriptors.
Security descriptor verification completed.
25057 data files processed. CHKDSK is verifying Usn Journal...
37141264 USN bytes processed. Usn Journal verification completed.
CHKDSK is verifying file data (stage 4 of 5)...
212208 files processed. File data verification completed.
CHKDSK is verifying free space (stage 5 of 5)...
42223974 free clusters processed. Free space verification is complete.
Windows has checked the file system and found no problems.
234326015 KB total disk space.
65039588 KB in 101616 files.
67860 KB in 25058 indexes.
0 KB in bad sectors.
322667 KB in use by the system.
65536 KB occupied by the log file.
168895900 KB available on disk.
4096 bytes in each allocation unit.
58581503 total allocation units on disk.
42223975 allocation units available on disk.
Internal Info:
00 3d 03 00 dd ee 01 00 d7 aa 03 00 00 00 00 00 .=..............
c8 00 00 00 2d 00 00 00 00 00 00 00 00 00 00 00 ....-...........
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
Windows has finished checking your disk.
Please wait while your computer restarts.
S: (Seagate 500GB Drive)
Code:
Chkdsk was executed in read/write mode.
Checking file system on S:
Volume dismounted. All opened handles to this volume are now invalid.
Volume label is Steamapps.
CHKDSK is verifying files (stage 1 of 5)...
170240 file records processed. File verification completed.
115 large file records processed. 0 bad file records processed. 0 EA records processed. 0 reparse records processed. CHKDSK is verifying indexes (stage 2 of 5)...
185364 index entries processed. Index verification completed.
CHKDSK is verifying security descriptors (stage 3 of 5)...
170240 file SDs/SIDs processed. Cleaning up 132 unused index entries from index $SII of file 0x9.
Cleaning up 132 unused index entries from index $SDH of file 0x9.
Cleaning up 132 unused security descriptors.
Security descriptor verification completed.
7563 data files processed. CHKDSK is verifying Usn Journal...
21237288 USN bytes processed. Usn Journal verification completed.
CHKDSK is verifying file data (stage 4 of 5)...
170224 files processed. File data verification completed.
CHKDSK is verifying free space (stage 5 of 5)...
51857488 free clusters processed. Free space verification is complete.
Windows has checked the file system and found no problems.
488281087 KB total disk space.
280513320 KB in 162459 files.
65636 KB in 7564 indexes.
272175 KB in use by the system.
65536 KB occupied by the log file.
207429956 KB available on disk.
4096 bytes in each allocation unit.
122070271 total allocation units on disk.
51857489 allocation units available on disk.
C: - The SSD
SSD Firmware -I Thought was up to date however new one has been released (end of april) So i've *just* updated this

Bios version is latest
Chipset is latest that Clevo / Sager have released (but theyre quite old..) its a HM67 express chipset.. and annoyingly it seems OEMs Customise whats available so Intel dont have a 'standard' download (unless im being blind! feel free to correct me)
Sata controller is part of the express chipset - so is reasonably outdated, neither Clevo (nor Sager, its american counterpart) has a newer driver on their site...
SMART = Pass
Drive S - The Seagate HDD
Seatools Result:
SMART = Pass
Short-generic = Pass
Long-generic = (not yet ran)
SFC
Pulls up no integrity violations found. (Ran twice just to be sure)
Security:
MSE and Windows Firewall only.
During doing the above, i got another BSOD (BAD_POOL_HEADER)
Dumps attached (middle is the BPH dump)
Also had a BSOD which pulled up pointing to NTFS.sys - did the C drive chkdsk after this (S was done prior) - ths is the latest dump. This occurred during a Malwarebytes scan (obviously putting load on the drive, BSOD was 'Page fault in non paged area')
System is a clean install, with SP1 on prior to installing drivers & third party apps (something interferes with the install of SP1 if done prior..)
Many thanks for any help, The machines starting to send me grey...!
Afterthought: Updating the SSD firmware shouldnt have messed with things in a way which would require another format - would you think?