Those cards don't run in SLI mode on Vista either, so the problem is probably somewhere else, presumably in the OS X-specific code where BlitzMax initializes the fullscreen mode. Since non-BlitzMax apps don't have a problem with doing that on OS X on that machine, it seems the bug is in BlitzMax.
For now, it would be ok to just see a fullscreen app work on the primary display. Of course, on the long run, proper multi-display support - as e.g. pyglet offers it - would be even nicer.
For now, it would be ok to just see a fullscreen app work on the primary display. Of course, on the long run, proper multi-display support - as e.g. pyglet offers it - would be even nicer.