8.3 File Name Problem

I have one user, WinXP SP2, who started having a problen copying files to a network share. He started getting prompted to change the filename to the 8.3 format. Other users did not have the problem to that share.

We discovered that if he did a fsutil disable8dot3 and set it to 1, the behavior disappeared. However, every few days the problem re-appears, and he has the set it back to 1 again.

Any ideas?