I personally don't agree with the statement, I believe it is the bad contact between the iPod's earphone jack and the plug causing the problem.
You can see from time to time, there are posts regarding to they can only hear one channel from the earphones.
May be it is the quality control problem, after hundred times of plug and unplug of the earphones with the iPod, the iPod jack's metal contact parts become lose, and created space in between the plug and the jack.
Consider setting up a mail-in repair for your iPod
http://depot.info.apple.com/ipod/
Or visit your local Apple Retail Store
http://www.apple.com/retail/
In case your iPod is no longer covered by the warranty and you want to find a second repairing company, you can try iPodResQ or ifixit (if you good to deal with electronic part) at your own risk
http://www.ipodresq.com/index.php
http://www.ifixit.com/ - for the part replacement (earphone jack)