Is this the first time that you are doing this export first time? if so my question at this point would be, did you execute the catlog, catproc scripts and other rebuld the java server objects and if you have the replication, then catrep. If you are using the oracle intermedia, you might require the ct...x patches. make sure you performed the some or all of the following above steps. It looks like some dependency mismatch, could be in catalog.

Hope this would help you.

Sam