Ultimate Fade-in slideshow (v1.51) overlaping with .png file

[Frogger]

1) Script Title: Ultimate Fade-in slideshow (v1.51)

2) Script URL (on DD): http://www.dynamicdrive.com/dynamici...nslideshow.htm

3) Describe problem: png image disapears over time

Just wondering if someone can help. I have been using the Ultimate Fade-in slideshow (v1.51) script which works very well. I have designed a page with a .png image file which over lays and sits on top of the random fading images using css. Everything works well but after some time (maybe 5 minutes) eventually the over layed image disappears. Why would this be and is there anyway we can prevent this from happening? I can provide links to website if needed.

Thanks