Hi
I have a similar problem, trying to load a forms-based app with a pre-loader.
I tried a different approach, I load my form-based app into a movie clip, and use that as the basis for my MovieClipLoader object.

Preloading works no problem this way, but then the forms and screens within my actual app do not operate correctly.

I know that forms and slides do not work with Scenes in Flash MX 2004. It's still a relatively new API, so I'm hoping they'll make a fix for it?

Anyone else have any ideas?