Panic or segfault in Samba

Ubuntu 10.04.4 LTS

samba:
  Installed: 2:3.4.7~dfsg-1ubuntu3.10

Samba seems to segfault at random intervals for no apparent (to me) reason. Below is a backtrace.

I'm really not sure what to say beyond this. If someone will let me know, I'll be glad to provide whatever other info I can.

[Thread debugging using libthread_db enabled]
0x0089e422 in __kernel_vsyscall ()
#0 0x0089e422 in __kernel_vsyscall ()
#1 0x006d7e63 in waitpid () from /lib/tls/i686/cmov/libc.so.6
#2 0x00676863 in ?? () from /lib/tls/i686/cmov/libc.so.6
#3 0x00ae0d8d in smb_panic (why=0xe69c7e "internal error") at lib/util.c:1486
#4 0x00ace2ae in fault_report (sig=11) at lib/fault.c:52
#5 sig_fault (sig=11) at lib/fault.c:75
#6 <signal handler called>
#7 0x00a2c201 in query_user_list (domain=0x219603a8, mem_ctx=0x218fffe0,
    num_entries=0xbff5989c, info=0xbff59898) at winbindd/winbindd_cache.c:1417
#8 0x00a161a2 in get_sam_user_entries (state=0x219cbff0)
    at winbindd/winbindd_user.c:692
#9 winbindd_getpwent (state=0x219cbff0) at winbindd/winbindd_user.c:810
#10 0x00a12d82 in process_request (private_data=0x219cbff0, success=true)
    at winbindd/winbindd.c:538
#11 request_recv (private_data=0x219cbff0, success=true)
    at winbindd/winbindd.c:811
#12 0x00a13a48 in rw_callback (event=0x219cbffc, flags=1)
    at winbindd/winbindd.c:621
#13 0x00a14fd0 in process_loop (argc=1, argv=0xbff59c94, envp=0xbff59c9c)
    at winbindd/winbindd.c:1115
#14 main (argc=1, argv=0xbff59c94, envp=0xbff59c9c) at winbindd/winbindd.c:1440