Gnu Backgammon Won't Start

I'll select the app GNU Backgammon to start but nothing changes and the icon isn't shown in the panel. I considered that my graphics driver was the problem but even after activating the additional driver nothing changed.

After running it in the terminal i got:

GNU Backgammon 0.90.0  May  1 2011
Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004 by Gary Wong.
Copyright (C) 2009 by Gary Wong and the AUTHORS; for details type `show version'.
This program comes with ABSOLUTELY NO WARRANTY; for details type `show warranty'.
This is free software, and you are welcome to redistribute it under certain conditions; type `show copying' for details.

(gnubg:6003): Gtk-WARNING **: Unable to locate theme engine in module_path: "pixmap",

(gnubg:6003): Gtk-WARNING **: Unable to locate theme engine in module_path: "pixmap",

(gnubg:6003): Gtk-WARNING **: Unable to locate theme engine in module_path: "pixmap",

(gnubg:6003): Gtk-WARNING **: Unable to locate theme engine in module_path: "pixmap",
The program 'gnubg' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadRequest (invalid request code or no such operation)'.
  (Details: serial 151 error_code 1 request_code 155 minor_code 19)
  (Note to programmers: normally, X errors are reported asynchronously;
   that is, you will receive the error a while after causing it.
   To debug your program, run it with the --sync command line
   option to change this behavior. You can then get a meaningful
   backtrace from your debugger if you break on the gdk_x_error() function.)

I am using Ubuntu 11.10