sysinstall / kernel crashes for at least 5 days

Hi...
i tried to install -current from snapshots.jp for more than 5 days but got
this reproducable error all the time.
If you try to delete a partition and create a new slice, than exit the
editor with 'q' it ends in kernel debugger, same if i use an existing slice
and try to enter the "distribution" section.

DDB output reads (this is copy/paste by pen & paper...):

Stopped at softdep_disk_prewrite+0x3b testb $0x10,0x7b(%eax)

>> comment: eax = 0

softdep_disk_prewrite(c302d000,c7e10968) at softdep_disk_prewrite+0x3b
ufs_strategy(cdc999cd,cdc999f8,c061c891,cdc999dc,c0857300) at
ufs_strategy+0x10d
ufs_vnoperate(cdc99dc) at ufs_vnoperate+0x13
ibwrite(c7e10968,cdc99bac,c0707a8e,c7e10968,0) at ibwrite+0x3d9
bwrite(c710958,0,0,c302f000,c302e9d8) at brwite+0x3d9
ufs_mkdir(cdc99bc8,cdc99cd4,c0632d3e,cdc99fc8,c2f84000) at ufs_mkdir+0x7de
ufs_vnoperate(cdc99bc8,c2f84000,c0857080,c302ce38,cdc99c1c) at
ufs_vnoperate+0x13
kern_mkdir(c18fc540,bfbd980,0,1ff,cdc99d40) at kern_mkdir+0x15
syscall(2f,2f,2f,bfbfd984,0) at syscall+0x217
Xint80_syscall() at Xint80_syscall()+0x1d

syscall(136,FreeBSD ELF 32, mkdir) ep=0x814ccb7,
esp=0xbfbfd96c,ebp=0xbfbfda00