This is a serious error on Filemaker Incs part. Sloppy coding. I went back to my NT4 machine and reset some of the fields in my app to have values from the start, and it worked fine after porting across to WinMe. I still believe it is a division by zero thing within Filemaker. My app is calculation loaded with engineering calcs. Be careful when programming calced values and if at all possible try to make sure any division type calc will not attempt a division by zero in repeating fields. I will continue this testing on the varius win platforms.