OG1,
Thanks for your video. Now we have some thought.
The PC installed silverlight 2.0 , the silverlight file browsing dialog is the 'modal' mode, which prevent user click other UI of the browser.
(To confirm it, please try this : Maybe the UI will be blocked even you click the 'Cancel' button on the file browsing dialog.)
So I think that is a silverlight bug. We are trying reproduce this issue. (Now we get silverlight 4.0 works fine)
Currently you can do one of these option to get avoid that issue :
A - use uploader.UploadType=Flash or uploader.SetAdvancedOption(UploaderAdvancedOption.NoSilverlight, ''true'') to prevent silverlight mode.
C - ask the users upgrade the silverlight version to 4.0
We will continue this issue, and find better solution.
Regards,
Terry