A fellow user maintains an Excel file on a Windows Server 2000 box
that is shared across a network.  This user accesses the Excel file
from his desktop which is running Windows XP SP2.  Frequently, he
cannot open his shared Excel file because it is locked by his own id.
This problem persists for hours but at the longest is cleared up on
its own by the next day.  He does not have the Excel file open and
there is no instance of process EXCEL.EXE executing on his desktop PC.

I have tried asking him to:
1. Close Windows Explorer because it
   can read data about the file and hence leave it open.

2. Reboot his PC

3. Login to my PC using his User Id

All to no avail.  I have little control over the Window Server 2000
box hosting the shared Excel file in question.  Is there anyway to
further isolate the problem?  For instance, are there known problems
with Windows Server 2000 opportunistic locking support?  If so, what
fix level was it corrected in?

Any help would be appreciated.

--Thank you,
--Mike Jr