I just did a fresh install of the 8.1 server on a Windows 2008 R2 server, created a backup job for a fresh install of another Windows 2008 R2 server, and let it run. It hung at building snapshot, after 24 hours, I figured it's fair to say its not going to end. After testing various things I can say it is a 1 to 1 relation with backing up System State. After toggling it off, backups performed as they usually would. From what I've seen, the client spikes to 100% cpu usage and just sits there until you kill it off by hand. I verified the firewall is open on the server, and it does transfer 100% of the data when system state is off(so it's not a network related issue). I can't say I've seen this before on Windows 2003 servers, so it has me wondering if there is some UAC/permissions issue going on.