Why do I have to continually reset my screen timeout setting to my preferred 2 minutes? It keeps going back to 30 seconds at least every day. Is this a known issue or am I missing something? Also, related to that...my screen dims after it seems like 10 seconds (whenever I'm reading something like an article). Then, it will go completely black after the 30 seconds. Is the dimming tied to the complete screen timing out? Or is there a separate function for the dimming? Thanks!