ZIP deleting wrong selections-plays only one selection

[bwphotos]

My zip is weird today. I delete a selection (audio book mp3) and something else is deleted. I keep trying to delete what is playing and something else on the list is gone' Also, no matter what I chose to listen to, only one particular mp3 plays...the one I am trying to delete. I see that the battery is at about 25 percent. Is this the problem? Does it become unstable at low power?