Strange issue with file corruption.

We have an "interesting" issue going in with a file server at one of our sites.  This is a MS Windows 2003 Standard X64 OS.

About two weeks ago users began experiencing file corruption issues on some Subversion files stored on the D drive of the server.  For those wondering what subversion is you can go here: http://www.svnforum.org/forum.php

I have run chkdsk, SFC, and a few other utilities in trying to determine whether there is a hardware issue.  Nothing came out in the results.  I have also updated our virus protection software an ran multiple full scans and again nothing.

The interesting thing about all of this is that the file corruption began happening 1 day prior to our experiencing a fairly severe outbreak of the Expiro virus at several of our locations. One of the symptoms we experienced at infected sites was file corruptions. Again, I have run about 4 full scans to no avail.

Any suggestions as to where I go next with this?  

I find it more than a coincidence that one of the symptoms of the Expiro virus is file corruption, but we had no problems detecting and cleaning it so I would think if indeed this server is infected we would have caught it with all the scans I have run.

I did reboot the server before every scan and again we have had no problems in the past detecting and cleaning the virus.

Thanks!