5G iPod too quiet...????

I have had my 5G ipod video for a little over a year and I have noticed that it seems to be loosing volume. I know it sounds weird but when i turn it all the way up it is not nearly as loud as it use to be.

I often plug it into a tape player so it can play over my stereo and even when i turn my stereo all the way up it still is quiet. I know that this is a new problem because i never use to be able to turn my stereo up that high without shaking my walls! Is there anything to do? has anyone else had this problem?

I don't drop it and it has a great protective case. It spends a lot of time in my glove box of my car plugged into my car stereo deck. I don't see how this could affect the volume.

 

I already tried that. I have the earbuds that the ipods come with as well as the sony earbuds and they both have the volume issue. As well as the tape thing I plug into the earphone hole on the ipod. So my conclusion is that it is an issue with the ipod.