I got a used iMac 8,1 20" early 2008 a couple of mott=nths ago. it was working fine and it has started to slow down a lot. and i mean a lot!! it came with the original leopard OS and i upgraded it online to its current state 10.5.8 it is running with 4GB of RAM. whenever i run multiple programs like transmission and movies or iTunes, it kinda slows down and the spinning wheel comes out a lot. should i change the ram and upgrade it? help!!