Screen turns black then pink!!!!!????

Hi there i recently upgraded my p,c with a new p,s,u (ocz game xstream 600w) and a new g,p,u (inno3d g,f 8800 gts 512),
every now and then the screen turns black then pink but doesnt revert back to normal i have to reboot to correct this!!
any ideas?
ive just upgraded the g,p,u drivers to c if this makes a difference!

thanx

jon