I understand that you are having an issue viewing you Slingbox on 2 seperate Macs since the latest SlingPlayer plugin update. The first thing you will want to do in order to in order to troubleshoot this issue will be to make sure that you have the latest Adobe Flash and Java Script. If the issue persists after updating Flash and Java, I highly recommend trying Google Chrome as the browser to see if this allows you to connect. Please get back in touch with us if this does not resolve the issue.
Hope this helps!
Sling Media Forum Moderation Team