panic: mutex pipe mutex not owned at ../../../kern/sys_pipe.c:414

Well, I managed to panic bento in under 12 hours of use, after Joe had
been using it for the past 2 months without problems :-)

panic: mutex pipe mutex not owned at ../../../kern/sys_pipe.c:414
cpuid = 0;
Debugger("panic")
Stopped at      Debugger+0x55:  xchgl   %ebx,in_Debugger.0
db> trace
Debugger(c068e1db,0,c068d7dc,e45d8bb4,100) at Debugger+0x55
panic(c068d7dc,c06911d0,c0691d1e,19e,c0691d1e) at panic+0x156
_mtx_assert(ce82bd40,1,c0691d1e,19e,0) at _mtx_assert+0xec
pipe_direct_write(cb040ac0,e45d8c7c,c0691d1e,372,1) at pipe_direct_write+0x541
pipe_write(cb02e83c,e45d8c7c,c692ed80,0,c7b0e640) at pipe_write+0x2d7
dofilewrite(c7b0e640,cb02e83c,1,8067000,31bd) at dofilewrite+0xfb
write(c7b0e640,e45d8d10,c06a40eb,3ee,3) at write+0x6e
syscall(2f,2f,2f,8067000,31bd) at syscall+0x2c0
Xint0x80_syscall() at Xint0x80_syscall+0x1d
--- syscall (4, FreeBSD ELF32, write), eip = 0x280ef2ef, esp = 0xbfbfe74c, ebp = 0xbfbfe768 ---
db>

It is running 5.2-BETA from Dec 1.  Any ideas?

Kris "Bug Magnet" Kennaway