I have a Dimension 4400 that came with 4 USB ports, 2 on the back of the case and 2 just under a hinged door below the power switch. The two in the rear are functioning fine but when I plug my new digital camera into the front ones it's not recognized. Nothing seems to work on the two in front. I plug the camera into the rear ports and it works fine. Any idea what's going on here? Thanks for any help.
John