Do I have a corrupt file system?

This is a very odd recurring problem that frustrates the hell out of a user. This user has a file that displays in finder. When the user tries to open the file it disappears from the finder window (does not open). If the user clicks on a different finder window or desktop it returns. This is a file that was saved from Excel (Office 2008) and appears to only happen with saved Excel files. I decided to look at it using terminal and it got even more strange. First is the output from 'ls' (the file in question is 'untitled.xls'): [quote] dhcp-102: Desktop username$ ls Amortization Table.xls To Be Input IRR_Calculator.xls UL Grid (also for AIM)1.xls Kaye_10mm_GSUL6.pdf ricer.doc Kaye_10mm_GSUL6_WS.pdf untitled.xls [/quote] I then tried doing an 'ls -l' on that directory and 'untitled.xls' did not show up. So I tried to remove the file: [quote] dhcp-102: Desktop username$ rm untitled.xls rm: untitled.xls: No such file or directory [/quote] Finally, I tried to 'save as' from Excel and that seemed to fix the problem. Regardless of the fact that it is only Excel that does this, it makes no sense from a Unix file system standpoint. How can any application create a file that behaves that way? I can only think there is some kind of corruption in the file system. Unfortunately, this is an OD mounted home directory that resides on a RAID array. Off hours I did an fsck-hs (it takes about an hour) on that array and it found nothing wrong. Does anyone have any ideas? TIA.