While all my wired headphones fit, the contacts do not work very well: if the headphone jack is ever so slightly bumped, the stereo sound goes out of one ear. I have on order Motorola wired headphones. If I have the same issue with them, then I will know the audio jack is faulty.
UPDATE 8/13/11. I received the Motorola stereo headset s and it works flawlessly; no more audio out problems when the headphone jack area is bumped. So if you are having audio connectivity problems, make sure to get headphones made by Motorola. I got mine for 2 cents on Amazon.com (with $5 shipping) from Original Wireless. Motorola 3.5 mm stereo headset Model SYN1302.