Client crashing in new Kubuntu

I recently went from Ubuntu 10.4 to a clean install of Kubuntu 12.04 and now the client crashes when I close a window.
This is the error:

The program 'openerp-client.py' received an X Window System error.
This probably reflects a bug in the program.
The error was 'BadWindow (invalid Window parameter)'.
  (Details: serial 62149 error_code 3 request_code 152 minor_code 3)
  (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 running a bzr branch of 6.0.3. I presume I am missing some key GTK library but I have other GTK programs installed that don't crash. Can anyone suggest what it might be?