Still can't play this game for more that 20 minutes without severe flickering.
Once this occurs if I alt tab then I have a very high chance of UT crashing so that's not a option.

I have a GeForce 7950GTX 512MB gfx card, I have disabled all ani settings in the gfx drivers, and set everthing to performance.

I have done a full re-install and re-patched and still will go wrong

Are there any other solutions ?

Cheers,
Steve.