One little hint, although it hasn't nothing to do with your problems: try thread read: if your cd drive can read PSX cd's without problems, use thread read, is smoother. And, as you are using IOCTL interface, it's better for you than async read.
__________________
"I'm living in a dream I can't wake from"
Core 2 Duo 6600 FSB 1066 | 2048 MB DDR2 PC2 6400 800 MHZ | NVIDIA 8800 GTS | Sound Blaster Audigy 4 | Seagate Barracuda 250GB SATAII+WD Caviar 250GB | Dell 3007WFP-HC 30" Widescreen