NetBSD-9 UP kernels lock hard

Hi,

After way too many panics with NetBSD-9 MP kernels, I decided to try a UP 
kernel, particularly since cpuctl offline doesn't work. However, UP 
kernels lock up hard right after messages about USB devices, which, on an 
MP kernel, is right where the kernel would finish booting and init would 
be started.

To be sure, I tried GENERIC MP and UP kernels from nyftp.netbsd.org from 
29-Jan (my own were using the source tree from 1-Feb), but got the same 
results.

When the lock-up occurs, I can't get in to the kernel debugger at all. 
This is on a dual processor Sun Fire v245.

send-pr, or does someone here know how to proceed?

Thanks,
John