When I read your report first I thought, that it might be a duplicate of the whole blt problem [1]. But I'm not able to reproduce your problem - neither with python-tk from Sid/Squeeze/Experimental nor with the fixed/unfixed version of blt. Are you running Squeeze or Sid? [1] http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=524149#37 Regards, Daniel