I also get this problem from behind an NTLM authenticated proxy at work.
If I switch to a network without the NTLM proxy the process quits and I'm back to normal.
I also had this problem with other processes like syncdefaultsd when behind the proxy.
While I'm going through the proxy I turn off iCloud.
Lots of things don't work behind the proxy, like AppStore.
I'm looking at using cntlm or ntlmaps (local proxy relay), and then using the Network settings in System Preferences to point to the local proxy, to see if that may solve it. Although our firewall blocks almost anything but port 80 and 443, so that could be an added problem.
I've used cntlm on Windows before and it is good, but I'll need to compile it for OS X, but not yet, not yet (later).