[BUG] theme-switcher aborts on exit

[Richard Hult <rhult hem2 passagen se>]

Whenever I press Cancel in the theme-switcher, I get a SIGABRT and the
following backtrace:

remove 0x4800006
remove 0x4c00004

Gdk-ERROR **: BadWindow (invalid Window parameter)
  serial 2632 error_code 3 request_code 10 minor_code 0

aborting...

Program received signal SIGABRT, Aborted.
0x40569871 in __kill ()
(gdb) bt
#0  0x40569871 in __kill ()
#1  0x405694b2 in raise (sig=6) at ../sysdeps/posix/raise.c:27
#2  0x4056ab13 in abort () at ../sysdeps/generic/abort.c:88
#3  0x400a83f1 in g_logv (log_domain=0x4032caed "Gdk", 
    log_level=G_LOG_LEVEL_ERROR, 
    format=0x4032cbe0 "%s\n  serial %ld error_code %d request_code %d minor_code
 %d\n", args1=0xbffff5f4) at gmessages.c:382
#4  0x400a84a2 in g_log (log_domain=0x4032caed "Gdk", 
    log_level=G_LOG_LEVEL_ERROR, 
    format=0x4032cbe0 "%s\n  serial %ld error_code %d request_code %d minor_code
 %d\n") at gmessages.c:399
#5  0x4030faea in gdk_x_error (display=0x8068188, error=0xbffff680)
    at gdk.c:1013
#6  0x403768b4 in _XError ()
#7  0x403752cc in _XReply ()
#8  0x40371129 in XSync ()
#9  0x4031c88b in gdk_flush () at gdkevents.c:2210
#10 0x40271418 in gtk_main () at gtkmain.c:458
#11 0x804c68b in main (argc=4, argv=0xbffff7f4) at main.c:23
#12 0x40563a07 in __libc_start_main (main=0x804c62c <main>, argc=4, 
    argv=0xbffff7f4, init=0x804ad9c <_init>, fini=0x804f01c <_fini>, 
    rtld_fini=0x4000aa00 <_dl_fini>, stack_end=0xbffff7ec)
    at ../sysdeps/generic/libc-start.c:78