ex* has had issues, but I've now seen two panics on netbsd-2 in less than 
a month:

panic: tcp_output REXMT
Begin traceback...
0x0042dec0: at tcp_setpersist+0xc8
0x0042dee0: at tcp_timer_persist+0x98
0x0042df00: at softclock+0x248
0x0042df40: at hardclock+0x314
0x0042df70: at decr_intr+0xfc
0x0042dfa0: at trapstart+0xaec
0xffffe750: at ADBDevTable+0x4bb8b388
trap: pid 362.1 (setiathome): kernel MCHK trap @ 0x2d6d84 (SRR1=0x49030)
panic: trap
Faulted in mid-traceback; aborting...dumpsys: TBD
rebooting

It might be that this is a slower system (180 or 200 MHz 603e), so it's 
more apt to get caught in some place where an interrupt isn't properly 
handled. Of course, this kind of stuff never happens locally - it only 
ever happens on my colocated machines! So it's hard to do any real 
checking.

Ideas, anyone?

John