I have a MacBook Pro 2.5 GHz with 2 gigs of ram. I've been getting lags on websites, and opening up programs and such. Sometimes a couple of programs would be running and one of the programs would lag, but the others would run fine. Then sometimes I go into my home video thing (with the remote) and it would play fine and the computer would go dim and then my screen won't come back and I would have to restart my computer. And then sometimes when I go to restart my computer, it would take a while (if it does) to restart. Sometimes I have to force shut it down and then turn it back on. could this be a software mal-function or is it normal?