I did find-file and got a dump:
#0 0x403376a1 in ?? () from /lib/libc.so.6
(gdb) where
#0 0x403376a1 in ?? () from /lib/libc.so.6
#1 0xbffff26c in ?? ()
#2 0x8154545 in Fset_window_buffer (window=153395800, buffer=152453272)
at window.c:3169
#3 0x80a1bda in funcall_recording_as (recorded_as=137013004, nargs=2,
args=0xbffff4a0) at eval.c:3197
#4 0x80a5cc7 in Ffuncall (nargs=3, args=0xbffff4a0) at eval.c:3238
#5 0x8083d06 in Fbyte_code (bytestr=136405992, vector=136406140, maxdepth=9)
at bytecode.c:416
#6 0x80a2902 in funcall_lambda (fun=136406348, nargs=1, arg_vector=0xbffff654)
at eval.c:3597
#7 0x80a1d34 in funcall_recording_as (recorded_as=136966016, nargs=1,
args=0xbffff650) at eval.c:3214
#8 0x80a5cc7 in Ffuncall (nargs=2, args=0xbffff650) at eval.c:3238
#9 0x8083d06 in Fbyte_code (bytestr=136325488, vector=136325576, maxdepth=7)
at bytecode.c:416
#10 0x80a2902 in funcall_lambda (fun=136325616, nargs=2, arg_vector=0xbffff7b4)
at eval.c:3597
#11 0x80a1d34 in funcall_recording_as (recorded_as=137381772, nargs=2,
args=0xbffff7b0) at eval.c:3214
#12 0x80a5cc7 in Ffuncall (nargs=3, args=0xbffff7b0) at eval.c:3238
#13 0x8086732 in Fcall_interactively (function=137381772,
record_flag=136894148, keys=136894148) at callint.c:949
#14 0x80a090d in Fcommand_execute (cmd=137381772, record=136894148,
keys=136894148) at eval.c:2584
#15 0x80c393a in execute_command_event (command_builder=0x82e5848,
event=139608684) at event-stream.c:4346
#16 0x80c4096 in Fdispatch_event (event=139608684) at event-stream.c:4685
#17 0x808a15c in Fcommand_loop_1 () at cmdloop.c:579
#18 0x808a322 in command_loop_1 (dummy=136894148) at cmdloop.c:494
#19 0x80a597f in condition_case_1 (handlers=136894260,
bfun=0x808a30c <command_loop_1>, barg=136894148,
hfun=0x8089c40 <cmd_error>, harg=136894148) at eval.c:1653
#20 0x808a3fc in command_loop_2 (dummy=136894148) at cmdloop.c:256
#21 0x80a585b in internal_catch (tag=136968520,
func=0x808a3c8 <command_loop_2>, arg=136894148, threw=0x0) at eval.c:1328
#22 0x8089e8c in initial_command_loop (load_me=136894148) at cmdloop.c:305
#23 0x809d231 in xemacs_21_0_i686_pc_linux () at emacs.c:1705
#24 0x809e781 in main (argc=1, argv=0xbffffc84, envp=0xbffffc8c)
at emacs.c:2122