The new hard drive won't slide in
I am installing a new 500 GB 7200 RPM Seagate SATA Hard Drive. I am at the point of sliding the new HD in the silver bracket back into the Mac, but it doesn't seem to want to go the last 1/2 cm or so. I don't want to force it as I am pushing pretty hard. When comparing the new HD to the old one, there is a difference in the area around the 4 copper pins (jumper block). The new one has a plastic collar or border (see http://www.seagate.com/images/support/en...), while the old one doesn't. Could this be making a difference?