2012-05-29 8:15 - edited 2012-05-29 8:17
Thanks for your post and sorry to hear of your issue.
Make sure the headphone jack is clean and there is no dirt or fluff in the jack. If you can get a small pin give the inside of the jack a clean to make sure nothing is in there. Then try to reinsert your headphones and see if this works.
If the problem persists and you have made sure the jack is clean and nothing in there then check to see if you have the latest software version installed. You can do this by using Nokia suite to check for updates. If no update exists then try to reinstall your current firmware. You can find a link to Nokia suite and guides on the below link:
Give this a go and let me know how you get on.