Execute a WebRequest in a Background thread while UI Thread is blocked

Question

Why does the following code executes WebRequests after 5 secs when the UI Thread isn\'t being blocked anymore? Thread.Sleep is in the UI Thread while both Instantia

Answer 1

I asked almost the exact same question here (which I'll close now that I found yours): DownloadStringAsync requires UI thread?

The answer is that ALL network code is ultimately marshaled to the UI thread in Silverlight before version 5. Unfortunately, even when I build against Silverlight 5, I'm still getting the same issue, so I'm still investigating...