When creating an Effort, with a Start date in the past, setting a Stop date give the incorrect message "Warning: Start must be earlier then stop". After closing all dates are set to 00.00.00. (system locale is Italian)
Fixed. If you'd like to test the fix before the release, see http://www.fraca7.net/TaskCoach-packages/latest_bugfixes.py (revision 5662 or newer).
It's ok, bug fixed.