Synchronise work between my blackberry curve 8350, Microsoft outlook and Window XP

I have a very genuine problem. I usually synchronise my work between my blackberry curve 8350, my Microsoft outlook and windows XP. Well I don’t know how this happens but all my work is usually given the wrong dates. For instance, some of the due dates assigned to my tasks recently are 12th January 3897 and 3rd December 1765. Surely, does this really make any sense? These are dates that are obviously unimaginable and now they are the ones allocated to my work. I would like to know if there is anyone who may know a remedy to this. Thanks a lot.