Clues maybe, answwers no.
Is there anything else going on with the XP system? make sure there is nothing else runnign at the same time.
You shouyld also do the the Loop 1000 times more than once. Their maybe some over head invloved in loading things up at first.
Hmmm 1000 X 0.236 ms? It took the XP 3.5 minutes?
You aren't doing any screen updates or anything are you?
Make sure you are timing only the loop, and not accidently timing some other fuction as well.
XP "should not" be that bad.
There has to be another reason.
Ben