Thank you very much for your feedback... the events are absolutely random. But i figure it out changing a lot of parameters, i dont know exactly what ive change, becaus e i change a lot of things but i guess its has to be the windows or the nvidia control panel... if i play in medium or high textures it doesnt affect.
The thing is now i play at 60-70 fps constantly, with no drops, but i cant reach the +100 fps, that i reached before.