Just upgraded my kernel to 2.4.13-ac2 with the preemptible kernel patch by Robert Love. Everything appears to be working correctly with SMP now, and my system does seem a little bit faster (although it's kind of hard to tell ;)). Anyway, here is a great interview with Robert Love describing the preemptable kernel patch and comparing it with the other reduced-latency kernel patch floating around.
Otherwise, things seem to be running okay. Still no luck with the DVD drive; I'm starting to think I've got a bum drive (it throws a ton of errors regardless of the DVD, player, configuration, etc). The strange thing is I can mount and read CDs and DVDs just fine; playing them is just a no-go.
Finally, I posted a no-documentation tarball of my mutt settings. If you're interested, you can grab them here. Please remove my email and name before using these files.