9.0-BETA3 lock order reversal in mount_smbfs

Attempting to mount a remote SMB share with mount_smbfs fails:

freebsd9b3# uname -a
FreeBSD freebsd9b3 9.0-BETA3 FreeBSD 9.0-BETA3 #0: Sat Sep 24 20:46:57 UTC 2011     root_at_obrian.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC i386
freebsd9b3# mount_smbfs -I smbhost -U xxx -W domain //smbhost/xxx /mnt
Password:
mount_smbfs: unable to open connection: syserr = No such file or directory

and displays the following kernel messages:

smb_co_lock: recursive lock for object 1
lock order reversal:
1st 0xc2ef4608 smb_vc (smb_vc) _at_ /usr/src/sys/modules/smbfs/../../netsmb/smb_conn.c:325
2nd 0xc2ffbc28 smbsm (smbsm) _at_ /usr/src/sys/modules/smbfs/../../netsmb/smb_conn.c:348
KDB: stack backtrace:
db_trace_self_wrapper(c0eff6ac,626d732f,2e2f7366,2e2e2f2e,74656e2f,...) at db_trace_self_wrapper+0x26
kdb_backtrace(c0a42bdb,c0f0300f,c29697b0,c29696e0,c76d298c,...) at kdb_backtrace+0x2a
_witness_debugger(c0f0300f,c2ffbc28,c2ff93df,c29696e0,c2ff9320,...) at _witness_debugger+0x25
witness_checkorder(c2ffbc28,9,c2ff9320,15c,c2ffbc48,...) at witness_checkorder+0x839
__lockmgr_args(c2ffbc28,80000,c2ffbc48,0,0,...) at __lockmgr_args+0x824
smb_co_lock(c2ffbc20,80000,2,2,c76d2b30,...) at smb_co_lock+0x73
smb_co_gone(c2ef4600,c76d2b88,c76d2b88,c76d2aac,c2ad5b00,...) at smb_co_gone+0x34
smb_sm_lookup(c76d2ad8,c76d2b14,c76d2b88,c76d2b30,c29f041c,...) at smb_sm_lookup+0xf0
smb_usr_lookup(c29f0400,c76d2b88,c76d2b94,c76d2b90,c76d2b7c,...) at smb_usr_lookup+0x98
nsmb_dev_ioctl(c2f76700,82fc6e6a,c29f0400,3,c2fce8a0,...) at nsmb_dev_ioctl+0x1d9
giant_ioctl(c2f76700,82fc6e6a,c29f0400,3,c2fce8a0,...) at giant_ioctl+0x75
devfs_ioctl_f(c2d417a8,82fc6e6a,c29f0400,c2c05e00,c2fce8a0,...) at devfs_ioctl_f+0x10b
kern_ioctl(c2fce8a0,3,82fc6e6a,c29f0400,6d2cec,...) at kern_ioctl+0x21d
sys_ioctl(c2fce8a0,c76d2cec,c0f493b6,c0eebb0e,246,...) at sys_ioctl+0x134
syscall(c76d2d28) at syscall+0x284
Xint0x80_syscall() at Xint0x80_syscall+0x21
--- syscall (54, FreeBSD ELF32, sys_ioctl), eip = 0x28193283, esp = 0xbfbfe35c, ebp = 0xbfbfe688 ---

Anything further I can do to help debug this problem?

-- Bob