Well, after a couple of days with them, I must say that it wasn't the Halo beta that was the problem. Nearly every program I have that has pixel shaders (Morrowind, tech demos, Aquamark) gives me BSODs on my GF4 Ti 4200. Back to 45.23.
Maybe NVidia can make these drivers more stable, but for now, I'm going to just save up for a Radeon 9800 Pro and a new mobo/processor.
Your welcome too bad I could not help ya fix it, you know I had trouble with omega's right up till the last two sets, but before that I always had a rough time never did figure out why. I am gonna wait till the det 50's are for real, but I am not expecting them to be designed for our cards.
I installed the Omega 1.45.23a today. I was running the official detonator 45.23 and found running Halo beta 1.5 that it was somewhat sluggish and slow. After installing the Omega's I have noticed more smooth gameplay and details are clearer.