> Here it comes, produced today with "GNU Emacs 24.0.93.1
 > (i486-pc-linux-gnu, GTK+ Version 3.2.3)\n of 2012-02-22 on zelenka,
 > modified by Debian".

Thank you.  Is it true that you can reproduce this with the given recipe
at will?  The combination of

 > Content of *Backtrace* before the crash:
 >
 > * (set-window-configuration wconfig)

and

 > (gdb) bt
 > #0  0xb7fe2424 in __kernel_vsyscall ()
 > #1  0xb6a65c16 in kill () from /lib/i386-linux-gnu/i686/cmov/libc.so.6
 > #2  0x08139d78 in abort () at emacs.c:394
 > #3  0x0819441e in mark_object (arg=139036542) at alloc.c:5706

seems to indicate a collector problem when recovering from a window
excursion.  Reproducing a collector crash, however, is usually very
difficult.

Meanwhile please try the patch attached to check whether it (1) solves
the original problem and (2) results in this crash as well.

Thanks, martin