When I plug the headphones that came with my N800 into the jack it doesn't go all the way in (there's a good millimeter or two of exposed metal). Is that normal?

Also, I don't get any sound through the Nokia headphones (4 pole/3.5mm). So, I don't know if they're jsut defective or not but, If I plug in other headphones (3 pole/3.5mm) then, depending on which set, sometimes I get sound in one speaker but, never both.

Thank you!