Yeah, I use to have the same kind of problems with CSS (supposed to help the designers, right ... lol )
Maybe try to change the class to an id like
#divscroll {
}
instead of
div.scroll {
}
Then you would have:
<div id="divscroll"> instead of
<div align="left" class="scroll">
sometimes it works.
I don't have the solution either, testing is the (long and painful) way or get some CSS GURU come and tell us THE truth.
But actually, is there a CSS GURU that can manage to comply to: IE Windows (say from 5.xx to 6.xx), IE Mac (from 5.xx to 6.xx), Mozilla, Firefox (from 0.9x to 1.xx), Opera, Safari, name them... It's a mess!
I think we should code our sites the best we can and remember that (whether we like it or not) more then 95% (this is not for starting a troll, I don't know the exact figures but on our server, some 100 sites we have more or less that average) are still with IE...
BTW, I could've seen the SIMON wasn't yours, not the same style, obvious, yours is MUCH better
Courage!
Cheers