Photoshop elements 12, missing slide show photos

I have put together a slide show of 180 photos with 4 integrated videos and music sound in Photoshop Elements 12.  When I play the slide show from the slide show editor, it plays perfectly.  But when I output the slide show as a wmv file and then play that movie file back, there are some photo black outs of some the the slides at the end of the show even though the sound keeps playing for the slide, but the photo is not there.  How can I fix this problem??  What is the problem?