I understand that you want to know if is there relationship between the Slingbox and the SlingCatcher firmware versions.
We always recommend to use the latest firmware version on our devices. With this in mind, I recommend you to verify if the Slingbox PRO is working fine for Internet Viewing. Most of the times, if you are not able to get the remote connection using the SlingCatcher, the issue might be related to the Internet Viewing settings.
With this in mind, I recommend yo to check the following links: