Windows can't stop your 'Generic volume'

I hate this message.
I know all about it, and that it is generally due to an open handle on the system for the drive. However, I ahve had some issues where there is no open handle and it still will not remove the drive. This issue seems to be new to Vista.

A few things I have tried:
handle.exe : --- Results in no open handles. Can't remove the drive.
ProcMon --- Results in no open handles. Can't remove the drive.
RemoveDrive.exe --- Results in no open handles. Can't remove the drive.
Unlocker --- Results in no open handles. Can't remove the drive.
Device Manger ito unstall the drive --- Requires a reboot. I am sure a reboot will fix the issue. Without a reboot, san't remove the drive.
Disk Management to remove the drive letter --- Says the drive letter was removed, but still shows up in Exporer. Can't remove the drive.
Restarted many services... MS and non-MS (like antivirus). However, if it was non-MS there would be a handle showing up. Only real option is an issue atthe OS level or something else MS that can access the drive at a very low level.

Anyone have any other good ideas?
I can't even find anything in ProcMon that will tell me how Windows knows that it can't remove the drive... lots of RegReads, and nothing that seems useful.

Well, I guess it is time to reboot so that I can work on this other drive....