That does seem odd although there was a post a week or so ago (sorry, no time to look up which) with a similar sounding problem - model failed but worked after edit.
If your model is simple - try creating it completely fresh and save with a new name. Then load the report and the model and see what happens.
With your existing model you could also try the "Show field Contents" (or is it "Show Contents of Field"?) option to see if that makes any difference.
I hope this helps.
[size="1"][ September 01, 2005, 09:23 PM: Message edited by: Grant Perkins ][/size]