Panics when compiling

I'm running an NFS 3.1_RC1 userland with a GENERIC 4.99.1 kernel on my 
Jornada 690. I've 128MB of NFS swap configured and I've been compiling up 
(some of) pkgsrc. My network card is a Linksys WPC11 v3 (wi0). At 
seemingly random times (sometimes after 24 hours of uptime, but sometimes 
only an hour), I've seen the machine apparently lock up (logged in over 
ssh), but the screen's been blank when I've got to the machine itself and 
I've hit the reset button. Today however, I caught it at a panic:

fatal address error (load) in kernel mode
  spc 0 ssr 400001f0
panic: general_exception
kloader: kernel file name: /netbsd
panic: tlb_exception: no copyin/out fault handler (page not found)
expevt=c0 va=c0077000 ssr=400001f1 spc=8c0766d6 lwp=0x8cf2ba4c onfault=0x0

Would I have more joy with a kernel that wasn't -current? Am I just 
hitting a lack of memory?

-- 
Stephen