>How can you delete two times the same file? Since the disk access is done on a single thread... I don't see any possibility.

I had to do this kind of mecanism to avoid File Access Denied error.

FUNCTION RemoveFile
LOCAL lcOldError
lcOldError=ON('ERROR')
ON ERROR A=1
ERASE ...
ON ERROR &lcOldError

So, I guess a collision was occuring before. Now, I don't have this message anymore. But, I suspect this is where the cause of the corruption file is.