I noticed that my wireless mouse and wireless keyboard won't operate on my macbook pro anymore, which is strange because they worked fine the day before. I read around on other peoples discussions and found the common feedback was to reset the PRAM. so i did this as it said, "cmnd + opt + P + R" during the grey screen, heard the 2nd start up sound and everything. Laptop starts up again and it did not seem to solve the problem. This is rather frustrating because I use my laptop almost 6 hours a day.