[ia64] panic at shutdown (unp_connect)

All,

I've been seeing the following panic on and off for a while.
Is this a known issue? Has anyone seen this before?

bigsur% sudo shutdown -r now
Shutdown NOW!
shutdown: [pid 1068]
bigsur%
*** FINAL System shutdown message from marcel_at_bigsur.pn.xcllnt.net ***
System going down IMMEDIATELY


Feb  5 15:33:05 bigsur shutdown: reboot by marcel:

System shutdown time has arrived
Stopping inetd.
Shutting down daemon processes:.
Stopping cron.
Shutting down local daemons:.
Writing entropy file:.
.

fatal kernel trap (cpu 1):

     trap vector = 0x14 (Page Not Present)
     cr.iip      = 0xe00000000440f5c0
     cr.ipsr     = 0x1010080a6018  
(ac,mfl,ic,i,dt,dfh,rt,cpl=0,it,ri=0,bn)
     cr.isr      = 0x400000000 (code=0,vector=0,r,ei=0)
     cr.ifa      = 0x48
     curthread   = 0xe000000028861600
         pid = 435, comm = ypbind

[thread pid 435 tid 100060 ]
Stopped at      unp_connect+0x580:      [M0]    ld8 r14=[r14]
db> bt
Tracing pid 435 tid 100060 td 0xe000000028861600
unp_connect(0xe000000061351630, 0xe0000000620eafc0,  
0xe000000028861600, 0xe000000060e1c5b8, 0xe0000000620eb140) at  
unp_connect+0x580
uipc_connect(0xe000000061351630, 0xe000000003e45480,  
0xe000000028861600) at uipc_connect+0x80
soconnect(0xe000000061351630, 0xe000000003e45480, 0xe000000028861600,  
0xe0000000044066e0, 0x48e) at soconnect+0x140
kern_connect(0xe000000028861600, 0x0, 0xe000000003e45480) at  
kern_connect+0x140
connect(0xe000000028861600, 0xa000000032b0f4e8, 0xe00000002899f500,  
0xe000000004682560, 0x48e) at connect+0x90
syscall(0xa000000032b0f400, 0xe00000002899f500, 0xe000000028861600,  
0xe000000004858a80, 0x62, 0xa000000032b0f4e8, 0xe00000000467c960,  
0x8) at syscall+0x440
epc_syscall_return() at epc_syscall_return
db>


unp_connect+0x580 is line 1005 of src/sys/kern/uipc_usrreq.c and the
panic indicates that unp2 is NULL.

-- 
Marcel Moolenaar
xcllnt_at_mac.com