I had the same “starting streaming” / “timed out” problem at my vacation home starting 1/1/13 with my Sony Google TV. I solved it yesterday (after a week of frustration) by going to the Spotlight Gallery web site and clicking on the Slingplayer app. It worked. Prior to doing this I did a factory reset, but I am unsure if that made a difference.
I returned to my main home today and my Vizio Co-Star has the same “starting streaming” and then timing out problem. My fix for the Sony unfortunately did not work on the Vizo so the problem persists.
I assume that this is a Google TV issue, possibly related to the latest firmware. You need to know that the Slingplayer that comes with GTV is not an app, but rather, it is a link to Slingplayer web site that is enhanced to support Google TV.
The enhanced web site apparently is not working. My calls to Sony and Slingbox were an utter waste of time - the support prople were clueless.
Slingbox continues to work fine with my Ipad, Android phone and computer.
I hope they fix the problem, or that a user solves it for them and posts the fix here.