Roaming profiles not deleting (worked in teh past)

This configuration has worked for over four years but about a month ago the
roaming profiles stopped deleting for one of my customers. I imaging that it
is related to a Windows Update, but I haven't been able to find any proof of
that.


Setup.

DCs are Windows 2003 with latest SPs & Hot Fixes

Workstations Windows 2000 Pro with latest SPs & Hot Fixes

The "Delete cached copies of roaming profiles" is applied to all
workstations through GPO.

The "User Profile Hive Cleanup Service" is installed on all workstations.

Disk drives are formatted as FAT32 so there's no NTFS permissions to worry
about (don't ask, it was before my time).

All users run under standard (restricted/limited access) user accounts. If I
temporarily add their domain account to the local Administrators group, then
the profile gets deleted when they log off.

Most of the profile is being deleted. But there are always the same two
files left behind.

%userprofile%\NTUSER.DAT
%userprofile%\Local Settings\Application Data\Microsoft\Windows\USRCLASS.DAT

If you log in as an administrator and try to manually delete the left behind
profile folder without first rebooting, you get a Sharing Violation error.
Which simply means that the files are still in use (open file handles).
After rebooting, the normal user has no problem manually deleting their old,
left behind, profile folders themselves.


TIA