ahh, i was too freaked at the time to notice the joke I already re-did the lights. The original scene, before i added paint effects ans some particles did the same thing. I deleted the lights and started afresh and now i see the same problem. I'm totally clueless.

Could it be hardware related? I have no idea. I'm rendering with both CPU's and i'm continuing to use the computer. I noticed for the most part Maya is using around 55% of both processors but it does rise for a few secs every frame to !00%, probably lights, paint effects and/or particles. Is there any chance if i'm using the computer during these periods it can effect the render? I'm clutching at straws here