[Zope] 2.2/OpenBSD2.7 runaway

Zope/Unix newbie here, so please be gentle. Apologies in advance if this is the wrong list for this question. I was having fun with Zope 2.1.6 on a LinuxPPC machine, then moved it over to a Zope 2.2, AMD-K6-2 box running OpenBSD 2.7. It ran fine for a week, then not-so-fine. Watching TOP, the Zope/Python process is consuming ALL available cpu time, rendering the machine completely non-resposive. Python 1.5.2 and Zope 2.2.0 were compiled from source. OpenBSD kernel was compiled with maxusers = 128 I get the feeling that this is one of those "oh, you forgot to flick that bit" things. I just can't find the right bit to flick! Any advice is welcome!