The "Internal server error" messages are usually caused by a bug in
the query processor. For example, see:
What version of SQL Server 2000 do you have ? If you have less than
SP4, install SP4. If you installed it already, install hotfix 2187
If the problem still appears, you can contact Microsoft Support (for a
charge, but if they see that the problem is due to a bug, they may
cancel the fee).