We currently have a support case open with Microsoft. The issue is Windows 7 Event Viewer giving what appears to be a false positive for Event ID 55 NTFS errors on the system partition. MS is saying that it could occur even though the disk and file system is fine. The development team is supposedly working to narrow down the issue. We are trying to find a pattern in hardware/etc to try to help us narrow it down.
Would you mind taking a moment and checking your Event Viewer (if you don't check it regularly) and see if your system log has ever logged an NTFS Event ID 55 error? This could be on a perfectly good system. If so, can you please post your mobo/processor/version of Windows 7, etc? A google search reveals lots of users with the issue and some say it causes a chkdsk at reboot for no reason.
If you have access to several machines, the more the merrier.