Lots of different possibilities here to explain your loss of connectivity, depending upon exactly what you were attempting to do and what the exact error message that you are receiving reads. This includes everything from a partial failure of your power supply to overheating of the SB to transient noise or congestion on your internet circuits to a loosening of the cables somewhere to the web browser that you are using to view the slinging video doing an "in-background security upgrade" to a version that is not yet support by the SlingMedia web browser plug-in. This last possibility did happen to me this week when Mozilla upgraded their Firefox browser version 7.0.1. I have "downgraded" the Mozilla browser on all of my computers back to Firefox 6.0.2 for the time being, because I was getting too many viewing timeouts.
CORRECTIOIN EDIT BY CHAKKARINEN
Many thanks to phrelin, who found the solution to the Firefox 7 update issue. He writes:
"After I installed FF7 in its own directory and clicked on my Sling bookmark and the "watch" link, it went through the updated add-on install routine. It works fine."