I would be interested to know what you think of Adobe Edge - have you tried the free preview of this? Sure, it's lagging behind Flash by several light years at the moment, but for basic open source animation and interactivity, it's quite promising. I'm waiting for the software to be able to handle HTML5 video and audio - then I might give it a serious run for its money.
Personally, when developing in open source, I do not even worry about what my work looks like in Internet Explorer! Explorer is just endlessly frustrating, even at version 9, with its own bizarre behaviours and quirks. All other browsers give a consistent result - give or take the odd padding or margin difference - so I'd rather develop for Chrome, Safari, Firefox and Opera before going back and seeing what IE is willing to make of my creative output.
to be a handy place to learn from.
Anyway. One of the main reasons for the existence of this forum is - at least I hope - to help each other out - as digital writers - with the barriers and frustrations of technology when we are trying to realise our creative visions. So if you are hitting stumbling blocks when developing your latest work - please post here!