If you don't watch it the explanation might be a little bizarre. What is happening is that anytime anything is converted to a symbol (mc, button, or graphic) it disappears from the stage. This makes it very difficult for me to design anything because I can't see it.
anyway, a while back this happened before, and I found a fix to it... I had to navigate to a folder in my computer and delete a bunch of crap (about 10,000 blank html files) in some folder... I just forgot where that folder is, and cannot seem to find the same thread I found that advice on.
I'm on a intel-based mac, with adobe CS4... help please!!!!
Ugh! That's definitely a bug. I've never seen it before. Please contact Adobe. They are pretty responsive to things like this, but they can't do anything if they don't know about it.
Have you tried doing a file search for .html? I can't remember how you do that on a Windows machine. On my Mac, I just use Finder to navigate to Applications/Adobe Flash CS4 and then type .html in the search field. When the search window opens, I specify that I want to just search the folder I'm in, and I tell Finder to search by filename.
Also, this is probably obvious, but have you tried uninstalling and reinstalling. That's what I'd do in your position.
Author "After Effects Expressions"
Co-author "After Effects For Flash, Flash For After Effects"
Artistic Director, Folding Chair Classical Theatre, Inc
Senior Flash Developer, Zeitbyte.com