samba - Mar 2005 - Signal 11 on activity from XP SP2 clients (Samba 2.2.8a on SuSE 9.0)

I've got two brand-new, fully-patched XP SP2 clients who are suffering a
mysterious malaise.  These two machines will cause a smbd panic when
printing or accessing files on a somewhat random basis.  

Now, the puzzling thing is that three other XP SP2 clients, including one of
the exact same configuration, have no issues whatsoever.  I've basically
ruled out hardware failure on the server, since it's these two clients only.

I'm at a loss... any ideas?

Here's one such instance in the syslog:
Mar 10 10:22:51 riffraff smbd[25378]: [2005/03/10 10:22:51, 0]
lib/fault.c:fault_report(38)
Mar 10 10:22:51 riffraff smbd[25378]:
==============================================================Mar 10 10:22:51
riffraff smbd[25378]: [2005/03/10 10:22:51, 0]
lib/fault.c:fault_report(39)
Mar 10 10:22:51 riffraff smbd[25378]:   INTERNAL ERROR: Signal 11 in pid
25378 (2.2.8a-SuSE)
Mar 10 10:22:51 riffraff smbd[25378]:   Please read the file BUGS.txt in the
distribution
Mar 10 10:22:51 riffraff smbd[25378]: [2005/03/10 10:22:51, 0]
lib/fault.c:fault_report(41)
Mar 10 10:22:51 riffraff smbd[25378]:
==============================================================Mar 10 10:22:51
riffraff smbd[25378]: [2005/03/10 10:22:51, 0]
lib/util.c:smb_panic(1135)
Mar 10 10:22:51 riffraff smbd[25378]:   PANIC: internal error
Mar 10 10:22:51 riffraff smbd[25378]:

Attached is a snippet of a log-level 3 smbd.log for this timeframe.  There's
too much text to post inline, but I think the error occurs right here:
[2005/03/15 10:52:00, 3] rpc_server/srv_pipe.c:api_rpcTNP(1408)
  api_rpcTNP: pipe 30607 rpc command: SPOOLSS_ENDDOCPRINTER
[2005/03/15 10:52:00, 2]
rpc_server/srv_spoolss_nt.c:find_printer_index_by_hnd(263)
  find_printer_index_by_hnd: Printer handle not found:
_spoolss_enddocprinter_internal: Invalid handle (OTHER:10056:11055)

(Pardon the two messages; I think these are two separate issues, and so want
to track them separately.)