My experience is this does not work reliably. I made the entry in the registry as described. I rebooted, and used a preexisting RDP shortcut which I had saved to my desktop that has alwauys worked. It still would not connect, and same symptoms as listed by others.
However, I have also discovereed something new on this: If I create a fresh Remote Desktop Connection, instead of using the shortcut, I can connect just fine. But I don't want to have to create a fresh RDP connection everey time I want to connect to any one of my dozens of servers. I am finding that any time I save the connection to the file system, that's when it breaks. After killing the black screen (when it hangs) on the first try, on the second try, it actually pops up a file system error.
So this (at least my issue) has something specific to do with storage in the file system. So the registry edit is not the full solution, at least for me. It's pretty useless if I can't save the connection to the file system. I hope someone else has had and solved this problem. I'll keep watching for a solution here.
Cheers,
-=Cameron