Keynote cannot play slideshow…

Turns out that you might have been accidentaly recording the entire time!  R-steveo to the rescue. “Littlequi,

I just had the same thing happen to me. Here is what I believe is happening– somehow you hit the command to record the slideshow, and you have been recording ever since. So under the File menu, choose “Clear Recording” and see if things don’t go back to normal. Just spent an hour trying to figure this out!”