I build MAME from source and would like to use the debugger to do some basic research on a few arcade games. When I run the MAME debugger-enabled builds with --debug, however, all I get is a black window and no activity. What do I do? I'm running Ubuntu 11.04 (I plan to move distributions later) building MAME 0.145 (this happened with at least one slightly older version too) and can provide other requirements if you ask. Thanks.