8.1beta3 performance

We're running 8.1beta3 on one server and are having ridiculous performance
issues.  This is a 2 cpu Opteron box and both processors are staying at 98
or 99% utilization processing not-that-complex queries.  Prior to the
upgrade, our I/O wait time was about 60% and cpu utilization rarely got very
high, now I/O wait time is at or near zero.

I'm planning to go back to 8.0 tonight or tomorrow night but thought I'd
check the pqsql-performance prophets before I gave it up.