I ran this script Advanced Gallery script (http://www.dynamicdrive.com/dynamicindex17/agallery.htm) on a clean page using only the demo instructions and it misbehaved (jumping around on the page) in FF1.0.4, one of the browsers it is said to be good for. I did this trying to help someone in this thread:

http://www.dynamicdrive.com/forums/showthread.php?p=9607

The problem and a solution I found are outlined there.