Rt-2-0-13 problem after upgrade from RT1.x

Hello all. I’ve just upgraded everything from a 1x version of RT to
2.0.13. I am now recieving the following error when trying to create a new
ticket via email or from RT itself.
RT::Ticket=HASH(0xa2e438) ->Create couldn’t set EffectiveId: No value sent
to _Set!Create failed: / /

Extra info:

OS: Solaris 8
Database: psql (PostgreSQL) 7.0.3
RT: 2.0.13

I followed the RT/FM on upgrading and all went perfect. Just I am now
having this issue.
Any help would be great.