I'm curious as to where you're running into the problem. Let's start from scratch.
First let's make sure the Slingbox has been factory reset. You can accomplish that by following the hard reset process in this article:
Wait a minute after the hard reset. If the Sling logo light is blinking, you know it's been hard reset.
Next, using a computer that is connected on the same network as the Slingbox, go to the following website to get the Slingbox set back up:
You may have already attempted this before, but it can't hurt to try again. If it doesn't work, I'm curious as to where the process goes wrong, and what error messages you receive. If you do encounter difficulties, let us know, and we'll go from there.
Hope this helps!
That video was most helpful!
If the setup process gets stuck there, it is most likely not the Slingbox itself, but rather the Slingplayer for Web plugin failing to load/launch. What you'll want to do before going to setup.slingbox.com is go to:
Once there, it should prompt you to download the Slingplayer for Web plugin (or, in your case, an updated version of said plugin). Once that's all said and done, you should be able to get farther in the setup site.
Here's a couple of articles concerning the web plugin for reference:
Let us know how/if it works!