Unfortunately, I found no menu options or settings pertaining to the left/right channels that fixed the problem.

I guess I'll have to send it in so they can take a look at it. Thank you for your help, though.
I went to Apple's site to request a repair online, but even though my iPod is still under warranty, I have to pay shipping fees since it's been over 6 months since my iPod was purchased. Seeing as I don't have a credit card, I have to bug somebody in my house to use theirs to pay for the fees. That shouldn't be a problem, though.
Thanks again for the help, guys! I'll let you know how it works out.