Bitlocker: BitLocker could not be enabled

I am trying to enable BitLocker on a Windows 7 Ultimate x32 system with TPM. I follow the Wizard and when asked to encrypt the drive I select 'Run BitLocker system check' and 'Continue' (see attached sreenshot).
The USB is inserted and contains the recovery key (.txt and .tpm). During reboot I get:

Windows BitLocker Drive Encryption Information
The system boot information has changed since BitLocker was enabled.
You must supply a BitLocker recovery password to start this system.
Confirm that the boot changes to this system are authorized.
If the changes to the boot system are trusted, then disable and re-enable
BitLocker. This will reset BitLocker to use the new boot information.

Otherwise, restore the system boot information.

ENTER=Continue

Windows then continues to start normally. After login I get an error message: BitLocker could not be enabled (see attached screenshot).
When I check TMP it shows as active, initialized and owned.

I've started out from scratch several times - same results. I can't figure out what the problem is.
This is driving me nuts.

Any help appreciated

Thanks

BIOS: A06
DELL: d420
Hard drive: System reserved 100MB NTFS, 27.84GB NTFS

TPM
Manufacturer name: BRCM
Manufacturer version: 2.10
Specification version: 1.2
Status: The TPM is on and ownership has been taken

I've since modified the group policy settings for Bitlocker to use a PIN.
I am still getting the same results.
I follow the wizard, select check the system, reboot, enter PIN, get the same "error" messages as shown in my previous post.

This makes no sense.

Any help?

I try not to use that program just for those reasons, true True Crypt you'll have a lot less trouble with it....

I use both on a regular basis and highly recommend NOT using EITHER - if you don't absolutely HAVE TO BY LAW.

Bitlocker / Truecrypt won't encrypt drives with active sessions, services or connections. Both of these should be installed to a machine after a fresh low level format and NO programs installed.

Both options require 100% disk resource and you may find errors not relating to what's really causing them with prior installtions.

Thanks for everyone's feedback
I am going to weigh my options.
I currently use TrueCrypt to create encrypted file containers, but I thought to try out BitLocker to possibly replace it with. Thought it would be a slam dunk since I was under the impression I met all system requirements to enable it.
I might just continue to encrypt my important files with TC and forget about the OS.

what do you think about BitLocker ?doenst make teh Hd slow or something like that ? couldnt the Hacker desencrypt !