Hi, I've only been using my new aluminium macbook for over 1 month, and it is starting to lag. I noticed that i was running 1 powerpoint document, 2 word doc, adium, firefox and vlc player which was not running, but it was lagging so much that i couldn't scroll my word doc. The rainbow circle kept appearing. I felt the body and it was quite hot. Could it be due to overheating? Does a keyboard protector contribute to the overheating of the macbook? What could be the reasons to the lagging? Thanks.