Hello,
Did you ever find a fix for this? I have the same problem as i try to deploy 5.5.1. We run AD authentication across a farm of OSX and Windows machines.
Config 1: Windows machines running in Proxy, OSX machines running in User. If i submit from an OSX machine, it runs fine across entire farm.
Config 2: Windows AND OSX machines running in User. If i submit from OSX, I get badlogin's on the Windows machines. If i submit from Windows, it runs fine.