Adding a pk to @group_id didn't help. I'm not sure on the distincts, it's not my code. Thanks, may give your other idea a shot.

Yes, it's a specific problem with some of the UDFs that return a few hundred rows or more. We have rebuilt indexes, perfmon, even let the tuning wizard have it's...

@GSquared: Thank you, great info there.

@GilaMonster: Yes, the particular example we're focusing on anyway...has gone from ~50ms execution times to ~1.5 minutes since the migration to SS2005.

Thank you for the responses.

The frustration point is that we apparently need to re-write ~100 stored procs to no longer make use of the UDFs that ran perfectly fine under...