before i put more RAM some bugs appear in doom3, it creatings plane bitmaps like particle effect, and apply a distorcion shader and i found this forum topic:
http://www.conitecserver.com/ubbthreads/showflat.php?Cat=&Number=473746&page=&view=&sb=5&o=&fpart=all&vc=1i think this can help, just create a normal sequence with alpha:
