We have an issue where one of our users is having sync issues with outlook, its having conflicts with the calender and he even lost the entire month of april from his calender in outlook

Need more info, BIS, or BES...

We are using BIS, office 2003 on windows xp

Try this, open the DM with the BB hooked up, goto back up and restore, then advanced, then the box on the right, device databases, clear the calendar events, disconnect, then pull the battery, then re-sync. See if this works.