I just have uninstalled Flash10 and installed Flash 9.0r124 instead.
I still have the same bug. In the "Browse" dialog, after clicking "Open", I'm asked for my credentials. If I do not provide them, i get the error message "Flash : The upload task is interrupted! http 401". If I provide them, the browser hangs ...
Question: As explained in the original post, we force UploadType = Flash. I'd like to force it to Silverlight to see if it can solve the problem, but when I do it, clicking the "Browse" button has no effect ... Do you know how to solve this?