Just to warn everyone using Windows 7 that in some cases Flash uses code that seems to be cached.
At a certain point in time I knew my code was OK, but still it did not work correctly.
I started looking at my trace results and suddenly discovered that it outputted code that was not in my sourcefile anymore.
To solve it, I renamed all AS files and then everything worked fine again.
Using Flash CS3 on Windows 7 build 7100.
what's the difference between a windows 7 browser and every other browser?
That's your browser cache. It has nothing to do with windows7.