RT: Tried your updated build.
D3D still gives me the same "out of memory" crash while loading a mission. Tried OGL. Improved performance over last time; missions will progress past the briefings and move to the actual sortie, but gameplay freezes after about fifteen or twenty seconds, and crashes to desktop. Noted some other odd behavior, like the previously-described "Hall of Mirrors" effect with the cursor, and the fact that my HUD would vanish whenever I fired secondary weapons. This was at 640x480.
I decided to try OGL in 1024x768, just to see what would happen. That was a mistake. Crashed again--this time while a mission was loading, like with D3D--but this was the most severe crash yet, one that had my screen continually flickering back and forth from the crashing Freespace to my desktop. It did this several times, jumping to FS whenever I tried to close an open window, only to flicker back. Finally, FS died a merciful death, and I was able to reboot.
Using 1024x768 gave me the same "out of memory" crash that D3D does before it magnificently exploded.