I've been watching slingbox every day for the past 2 weeks and the image filled up the screen. Suddenly yesterday it no longer fills up the screen. There is a blank space along the top and sides. I'm watching HD channels. MAC lion 10.7.2. I tried it in Chrome and Safari and changed the display settings.
We understand that you are having issues with the image size using Watch at slingbox.com. First, I recommend checking the settings of the
Set-top box: confirm the resolution and the zoom feature on it. Have a look at this link, it will help you to adjust the resolution and the zoom on the SlingPlayer: