I understand that you are having some issues in order to get your SlingCatcher up and running.
Most of the times, this issue is related to the available bandwidth. If you are using two SlingCatchers in order to get the signal from a Slingbox PRO-HD, they will require a higher amount of your bandwidth. If it is not enough, the video signal will be affected. With this in mind, I recommend you to check your available bandwidth and contact your ISP in order to know if is there any kind of restriction.
I also recommend you to check this link in order to get the information about the requirements for the Slingbox PRO-HD: