Thanks to a crash log that was emailed in (cheers Justin) I may have finally solved the black screen bug, though this still needs confirmation.

Basically, the bug seems to boil down to a 'NaN' (Not a number) glitch, where the currently selected marine is moved to a set of co-ordinates that don't actually exist (hyperspace?) because of a mathematical error (divide by zero etc) and the camera is dragged with him. Since the camera is in a place that doesn't exist, it can't render anything, and hence everything goes black.

So, it would be really cool if someone who was getting the black screen bug before could confirm that it's gone. Exact same method as before:

1. Download the just uploaded Derelict 1.2 RC3 (from here) OR just copy the Derelict 1.2 RC3 executable (here) over top of your existing Derelict 1.2 RC1-2 installation.
2. If you get a black screen bug, press CTRL-F4 to quit
3. Pressing CTRL-F4 also produces a crash report (crash.txt). Email that directly to me (earok3d at gmail dot com) along with details on the OS, Graphics Card, Ram and CPU in your computer, as well as what you were doing in the game at the time of the crash.

Really hope I have finally nailed the sucker on the head!