strange, never experienced anything described in previous posts neither on my pre-production N900 or the retail one.

Tried with multiple head phones, nokia stock ones. sennheister cx 300 II. sennheister cx500, sony v700dj, shure E2c, Klipsch Image S4(i)
No problem what so ever luckily enough.

Tv-out jack sticks out a bit and dont go all the way in, but make sure if you got problem to have correct tv-out setting.

One of the best in-ear phones i ever tried (atleast in the "normal" price range) are the Klipsch Image S4 and the (i) version works excellent as a headset with the N900.

Sounds strange that the phone dont find the ear-phones if you unplugged them and then reconnect them at a later point.

Any chance anyone of you installed any other media player then the original one that might cause this problem?