My N800 has some issues with the headphone jack. It seems to work OK with the 2 sets of headphones I've tried but with 3 different line out cables I get mixed results - either no sound or minimal muffled sound at full volume.
(I know the problem isn't the receiver or the cable since an ipod works fine; I've tried various permutations to prove this.)

I searched around here and this seems to be a known issue with the N800, i.e., the headphone jack. So, would sending this in for warranty be worthwhile? Or am I likely to get back a similar working unit?

I really like my N800 and I now have an line in jack in my car stereo so I would like this to work...