Either, I think in general SMP is tough to get stable. People with more experience will hopefully reply and explain in more detail. For now I, personally, would disable smp on freebsd just to keep it stable.
I just dont know if this will keep it stable or not. Others are reporting that the bug is in ttwakeup and the other is that its a bug in IPF, which I currently use....
Thats why I'm at a dilemma right now. Do I keep things as they are, turn SMP off on FreeBSD 5.4, and risk problems in the future? Or do I switch to OpenBSD now, hope it works, and have a stable solution while FreeBSD becomes more stable.