I had my hard drive replaced by Apple (covered by the warranty thankfully) and ever since it has been acting a bit strange. What I mean is it can be occasionally unresponsive (i.e. slow screen wake up response when lid is opened, beach-ball'ed without many apps running) and outright underperforming for its hardware specs... I was curious if it was possible to transfer a bug/virus through the Time Machine backup? I don't think this is likely but was always curious if this could happen anyways. I don't know what is causing my MBP to act so strange. It used to be so speedy and reliable, I should probably buy more RAM.