I can't tell exactly what the problem is based on what you wrote but given that, it sure seems like a tonearm set up problem. I would start over again on the setup.
3 responses Add your response
"It works fine until it gets toward the end of the record, at which point it will start skipping and the arm will not advance anymore."
Sounds like an open and shut case of something is restricting the travel of the tonearm at the inner grooves. Should be straightforward to identify that. Could be tonearm wires; the cuing device; the mount being twisted too far to the right, away from the spindle; problem with the pivot bearing itself. You don't say what tonearm you are using. This is probably not a problem with the DD30 itself but with the tonearm.