netbsd-5-beta crash

[6bone%6bone.informatik.uni-leipzig.de@localhost]

hello,

my kernel NetBSD 5.0_BETA (checkout at Dec 23) crashs sometime with:

fatal page fault in supervisor mode
trap type 6 code 0 rip 0 cs 8 rflags 10202 cr2  0 cpl 6 rsp 
ffff800068b6fae0
kernel: page fault trap, code=0
Stopped in pid 0.2 (system) at  0:      invalid address
db{0}> trace
fatal page fault in supervisor mode
trap type 6 code 0 rip ffffffff8052dc0c cs 8 rflags 10246 cr2  0 cpl 8 rsp 
ffff0
kernel: page fault trap, code=0
Faulted in DDB; continuing...
db{0}> trace
fatal page fault in supervisor mode
trap type 6 code 0 rip ffffffff8052dc0c cs 8 rflags 10246 cr2  0 cpl 8 rsp 
ffff0
kernel: page fault trap, code=0
Faulted in DDB; continuing...
db{0}> reboot
syncing disks... panic: assert_sleepable: interrupt 
caller=0xffffffff804b5f99
fatal breakpoint trap in supervisor mode
trap type 1 code 0 rip ffffffff8052c335 cs 8 rflags 246 cr2  0 cpl 0 rsp 
ffff800
Stopped in pid 0.2 (system) at  netbsd:breakpoint+0x5:  leave



Any ideas what the problem could be?

Thank you for your efforts
Uwe