So I successfully installed 4gig of memory as well as a 320gig HD. Before snapping the cover back on, I powered it up and made sure it still powered on. Looked good. So since it was a new HD, I then tried to put a dvd into the slot to load the OS. It wouldnt go. Its like something is blocking the opening. Have any of you ran into this? Im dreading taking this thing apart again.