Hi Bruce, I was putting together another post for the list (which is currently awaiting moderation since apparently my attached project files were too large) when I encountered some strange behaviour in Artemis. I tried opening my project file on my second PC to check that it would open fine for other members of the list. But by simply opening the project and clicking Fit, I was getting different results for my guess parameters on the two PCs. Both PCs are Windows 7 and updated to Demeter 0.9.13. Here is a link to the project file (trying to avoid size limitations for the list this time) http://dl.dropbox.com/u/10663174/ZnO.fpj and I will attach a screenshot of Artemis demonstrating what I am talking about from my two PCs. Since I am working to determine S02 and it is very different on each PC, I am hesitant to trust any of my results right now. Thanks Jeremy --