hmmm... well, a while back my zune HD's screen acted funny when I had it on my bed and I started touching it. (wait, that sounds wrong)
I was listening to music and I went to the menu, but I was playing psp, so... I had it on my bed by my side, and I tried to go to trough the menu and it pressed things I didn't press, but when I picked it up, it worked great... but that was only one time... Now that hasn't happened.
But yours sounds like maybe the screen is not working properly..
but, I would say, try it one last time. 3rd time is the charm!