M14x gpu unstable

I have the GT 555m, and downloaded evga to overclock. At first it worked perfectly, setting the core clock at 740 from 590. The next day, i could not change my core clock speed at all, and the speed would switch between 590 and 202, sometimes even going down to 50. So I updated the graphics driver to 280.26, and the problem continued. Then I uninstalled all the graphics drivers and re installed. This fixed the problem for about an hour, but the speed went back down to 202 and won't change.
I am a noob, and i dont know what to do.
pleeease help

 

The speed changes depending on what you are doing, that's why some overclocking programs may show a downclock after overclocking at some time. The increments i've seen are 51mhz, 203 mhz, 590 mhz, my current overclock. It changes for when you watch movies/youtube or other small tasks. I think if you're in game, but maybe staying at the main menu or another non gpu intensive screen, it'll downclock, and the drivers only allow it to go back to its factory clock (590) and not your current overclock. I could be wrong, but that's my take on it. Download MSI afterburner and gpu observer widget. After burner is easy to use too.