4th Gen Ipod volume doesnt work suddenly with audiobooks

I was listening to an audiobook last night when the sound suddenly went out. At first I thought it was my headphones, after checking them on another device I ruled them out. I plugged them back into the ipod and tried an app to check the sound. It worked fine. Then i tried playing music, again works perfectly. I went back to my audiobook, still no sound. Tried adding a different audiobook, still no sound. The problems seems to be only with audiobooks. I even went into options and upped the volume 100+, with no results. This ***** because listening to books while I do chores is what i primarily use my ipod for. Please help.