Only half of my contacts + Calendar sync to my Blackberry

Hi.

My blackberry device is only receiving half my contacts and calendar entries.
But is receiving emails fine.

The device synced up correctly and finishes but when I view my calendar entries and contacts I only see half of them on my blackberry.

Current setup is IMAP and I am using a blackberry device model : 8300.

I'm using an BES 4.1.4 server.

I have a large calendar and around 3000 contacts in a categorizes format.

Has any one come across this problem before ?? Could it be that the categorizes format could be causing the problem ??