Me too. They slip. Fixing mine again now. Go to www.kuro5hin.org/story/2004/3/24/45212/6874
Years ago, my son fiddled in the back and fixed it; my memory says that you can use this fix for AIWA CX-NMT70 or NSX-MT75 or NSX-MT70 as they are so similar. Make sure your problem is not just a dirty head, etc. by following Kuro5hin's symptoms. Get a phillips head and fine tip marker. Be sure to read the whole long article and the back and forth afterwards, as the author says he'd update the initial response if he could.
marybeth falkenstine mears, April 2008