Sorting Feature in Crystal Reports 2011

We recently upgraded from Crystal Reports XI to Crystal Reports 2011. When doing compares of our reports after the upgrade we noticed that some reports were sorting differently in the new version than the last. This behavior wasn't consistent, or at least we couldn't find a pattern. Sometimes it was only a couple records switch around, and other times there were more changes.

Can you tell me if the sort functionality changed between the two versions? If so, can you describe specifically which situations are expected to behave differently?

Thanks!