Can't add new Task and problem syncing tasks with pda

[Taj Haslani]

Hi,
I am not able to add new tasks. It gives me following
error:
Couldnot complete the operation. One or more parameter
values are not valid.

I am also having syning with my PocketPC PDA. Some tasks
are not getting syncronized.

Any help will be appreciated.
I am using Outlook 2002 with SP2 on Windoes XP with SP1.

Thanks

Taj Haslani