I was having the same problem on my mac. After calling slingbox, they said it was a specific issue related to my computer set up. That led me to consider that the internet filter (k9 web protection) I had installed on my computer may be causing the problem. I first tried to disable it but I was still getting the P-2 error. Then I completely uninstalled it and that worked. So I guess it comes to down to something with my internet filter blocking the slingbox app on my computer.