I found a method on another site for making remote rollovers, similar to the tutorial I later found on this site. It seemed perfect for making an image gallery with thumbnails. After dutifully shoehorning it into my code (with a bit of modding along the way), it worked like a charm in Firefox! Not so much in IEv6, though… although the demo on both of my reference sites seemed to work just fine in IE. (I keep reading about display: block as being important, and it’s in there, but still…)
The webpage can be seen here, and the stylesheet is here. I’m still an utter noob when it comes to CSS… a few days ago I barely knew my span from a hole in the ground. Thanks for the help! This is driving me nuts. Anybody looking at my page will probably still see some issues I’m having with PNG transparencies in IEv6… but that’s another story.