hello, everyone!! I recently purchased a manufacturer-refurburished Acer iconia a500 from the acer outlet store on ebay. I'm very excited about my new tab, except, the screen keeps flashing from bright to dim and then back again. It doesn't do this constantly, but just enough to be mildly annoying. My questions are, is this normal? Does anyone else's tablet do this? Please help!! thanks to everyone in advance for your advice!!