I had a look around and couldn't find anything relating to this problem...
I just encountered it this morning whilst walking in to work, my ipad was in my backpack and I was using itunes to listen to an album when the audio started jitering uncontrolably, the volume kept becoming very loud every split second or so, then I just started to get clicks and pops through all of the audio. At first I thought it was my headphones but I've tested it at work with someone elses and it still happens.
Has anyone else encountered this? It is something to do with the ipad not being able to be used like an iPod due to the disc not being able to be read when on the move?