Possible hammer problem

[DFBSD]

The lighttpd process got stuck in the select state unkillably. I decided to 
reboot and got a panic.

syncing disks... 87 87 87 87 87 87 87 87 87 87 87 87 87 87 87 87 87 87 87 87
giving up on 1 buffers
Debugger("busy buffer problem")
Stopped at      Debugger+0x34:  movb    $0,in_Debugger.3949
db> trace
Debugger(c05382b5,c053829c,1,0,0) at Debugger+0x34
boot(0,caf18d34,c04d2fdd,caf18cf0,6) at boot+0x1e2
sys_reboot(caf18cf0,6,55d93,0,c9708c58) at sys_reboot+0x23
syscall2(caf18d40) at syscall2+0x1e9
Xint0x80_syscall() at Xint0x80_syscall+0x36
db>
Needless to say, lighttpd serves from a hammer partition and also runs from 
another. Kernel and vmcore are also available:

http://160.114.134.7/~szg/crash081111/