-current troubles on Dell Latitude C600

[Olev]

I am having troubles installing -current from JSNAP -current iso images 
on my Dell Latitude C600 laptop. Everything is ok when / has not been 
set on softupdates, but when softupdates is activated on / (and / is the 
only partition besides swap) I get an error during extraction of base.
kernel: type 12 trap, code=0
Stopped at 	vm_page_set_invalid+0x90: 	incl 	0x5c(%eax)

That traces to:
vm_page_set_invalid(c0fc9a70,0,1000,54a,0) at vm_page_set_invalid+0x90
brelse(c78a4f40,c0fc00e0,c0fc00e0,c2ca9280,c78a4bd0) at brelse+0x56b
softdep_disk_io_initiation(c78a4bd0,d213fba8,246,c053e430,c0fc00e0) at 
softdep_disk_io_initiation+0xc4
spec_xstrategy(c2c7e490,c78a4bd0,c053e430,d213fbd0,c78a4bd0) at 
spec_xstrategy+0x114
spec_specstrategy(d213fbe0,ffffffff,c0fc00e0,4,c78a4bd0) at 
spec_specstrategy+0x72
ufs_strategy(d213fc24,d213fc5c,c037bf57,d213fc24,1) at ufs_strategy+0x110
ufs_vnoperate(d213fc24,1,c053e430,35a,c032b300) at ufs_vnoperate+0x18
bwrite(c78a4bd0,0,c053e430,694,2863c0) at bwrite+0x427
vfs_bio_awrite(c78a4bd0,0,c053e430,884,c2a18130) at vfs_bio_awrite+0x241
flushbufqueues(0,0,c053e430,10e,64) at flushbufqueues+0x22c
buf_daemon(0,d213fd48,c053640c,314,0) at buf_daemon+0xdc
fork_exit(c037e630,0,d213fd48) at fork_exit+0xcf
fork_trampoline() at fork_trampoline+0x8
--- trap 0x1, eip = 0, esp = 0xd213fd7c, ebp = 0 ---

Any ideas? With softupdates disabled everything works. I have tried the 
last 3 isos on JSNAP of -current and every one of them fails when 
softupdates is enabled.

Olev