This issue seems to me to be similar, and potentially related, to a WinXP / DDE issue I posted June 2 ("Request to Word 97 and WinXP users").
While Word may be the problem for my issue, we do see some strange file locking issues under Win XP only.
In that other posting a DDE InsertFile command is not allowed access to the CVI file it created, wrote, and closed. ("Access denied")
In this thread, it seems that the reported issues are all programs hanging while trying to access text files that they created.
I'd encourage people to try out the posted simple .c file from the other thread, esp. on Win XP platforms with Word 97.
Hope this helps us all.