Mine is starting to do the same thing but I haven't done anything yet about it. I have used PDASmart.com in the past for other unrelated repairs and they were very good and reasonable.
Try putting A LITTLE switch cleaning fluid or WD 40 on the jack plug and then inserting it into the jack socket and pulling it out and re-inserting it several times.
May not work but it is easy to do and worth a try. Make sure that the jack plug is damp rather than wet.