Sorry to hear that you're having trouble with Watch on Slingbox.com. Let's see what we can do to get you up and running again.
First thing: Try resetting your Slingbox ... often that can help. Press and release the Reset button on the back of your Slingbox. When the two red lights on the right side of your Slingbox stop blinking and start glowing steadily, your Slingbox is ready.
Next: If that doesn't help, here are some articles to help you ... starting with making sure that you have what's needed.