I got a XMB forum setup, i dumped the tables to the database from my old server. When I try to post something it gives the error "Duplicate entry '32767' for key 1"
I looked at the tables and all but can't seem to find anything wrong. Any ideas? :)

It means that the post is getting assigned an id that is already used up , since the id is a probably primary key, it must be unique.
Try analyzing the table with posts (not very sure what the name is in xmb) and repairng and optimizing it with phpmyadmin