If you are still experiencing issues with the SlingCatcher you purchased, I encourage you to check the following link for some SlingCatcher troubleshooting and, if the issue persist, contact our Technical Support Department.
I hope that helps you!
I was having this exact same problem and was able to fix it. Apparently my SlingCatcher is from the UK and I am using a TV from the US. For that reason, the screen resolutions are different and I needed to change the resolution output from the SlingCatcher to match my TV. It was difficult to do as I could hardly read the words on the screen, but I went to Settings -> Output Resolution -> then picked the top option (480i for the US). I got that information here: http://support.slingbox.com/get/KB-5000056.html