hi, i have a refurbished macbook, that i got in April of this year. Lately it has been acting up, with some of these problems: -When i open it from sleep, the screen remains black, and i have to restart it to get it back to normal. -The top menu bar is sometimes pushed to the left, leaving empty space on the top side. -Firefox has been rendering web pages very slowly, and half of them in basic text. I've uninstalled and reinstalled it, so im not sure firefox is the problem. I've been considering taking it to the apple store, I'm still in my 90 day period,but im not sure if these problems constitute a trip to the store, or if they could be remedied with other methods. Specs are: 2.0 Ghz, 1 GB Ram, Combo Drive Thanks for any help.