I've read about the black screen lockup; not the case with me.  I know pc's cuz I've worked on them for past 10 years, but this one has me puzzled.
There is no pattern; I'll be flying, no buttons pushed, nothing (maybe in autopilot or whatever) and bang!  Blue screen.  Not the blue screen of death, but a bright blue screen wherein I can still hear and type (but I can't see anything at all; bright blue screen).  In other words, I could keep flying all day, crash, bail, bomb, whatever, but cannot see anything.  It's just video.  I've tried every tweak; fps, color depth, reinstalling video card, direct x, no irq conflicts, 192MB ram, 32 MB Elsa Erazor video; drivers current, even tried older ones.  
Guesses?