I use a Mac; I had the same problems with getting the episodes everybody else did, until we got the manual workaround, which I use.
So I did the manual installation for Episode 5. However, when I entered the game to install it, it showed both Ep 5 and Ep 2 as "Purchased" but not installed. I installed Ep 5; it seemed to work.
Upon trying to go in and play, the game crashed.
Now when I go in and try to install either of them (both are on "Purchased"), they go "Downloading 0.00%" then go to "Downloading 0%"
Please lend assistance.