I've got a site where all the rollovers work like this:
When the page first loads, the "normal" image loads. In this case, it's just a text link.
On mouseOver, I use a image.src='new source' (this is pseudocode, but you know what I mean) to change the normal image to an animate-once GIF. The animation is of a colored panel sliding in behind the link text.
On mouseOut, the image.src changes to another animation, this time of the colored panel sliding back off the screen.
After allowing enough time for the animation to run, a timer turns the "slide-off" image back to the "normal" image.
The result is that when you hover, an animated element slides into the screen; when you mouse off, the element slides back off. Simple, right? And it works like I expect in IE and Opera.
Now, in Netscape 6, the gif animation is not running every time the image.src changes. Instead, it's running just once, ever. If I mouse over a link again, I only see the last frame of the intended animation.
I'd be pretty crushed if I learned that this was how animate-once GIFs are supposed to work. I was hoping that I'd found a simple, non-Flash, non-dHTML-intensive way of doing this simple slide-on-slide-off effect.
If you have a strong stomach, take a look at the site. But please please please ignore the Flash intro, it's frighteningly bad, I had nothing to do with it. Same with the popup Flash navigation that occurs if you click the "band" link.
<edit>Also note that some of my JavaScript is clean and elegant, and I'm proud of it, and then some of it is just barely good enough to work, because I'm under a time limit, and I'm getting paid half a pittance for this entire site. If you see an actual error, please warn me.</edit>
The site's very nearly done, and if I got a serious critique on it right now, I'd just feel helpless, since it's got client signoff and it's going live in a few days. Once it's completely out of my hands, I'll post it in Site Reviews and encourage a full feeding frenzy.
[This message has been edited by Perfect Thunder (edited 11-14-2001).]