I've had this problem before and I am pretty sure DBP using a temp file was the culprit. It's been so long and I don't have DBP in front of me, but I'd look in temp folders for something like 'temp.dbp', 'temp.exe', or something along those lines.
It could possibly be a application privilege issue also. Make sure that you are running DBP in admin mode? It could have the old file in Program Files and not allow DBP to delete/replace it.
Not sure, but hopefully this info gives a place to look into! Best of luck!
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