I'm having an odd problem with a new x64 2008 Ent install, in its own domain, when attempting to connect to a share on a workgroup Server 2003 (Ent 32 bit), even with a valid password, it fails to connect. When attempting to map the drive in cmd prompt, it fails with error 86. The two machines are on the same subnet, gigabit switch, ping works fine.
The share works fine from any 2003 or XP machines.
When attempting to map a drive from this same 2008 box to another similarly configured 2008 box (Ent x64, own domain, different from first box), the same thing happens.
Both machines are sole DCs in their own domains, running WDS, FRS, and Hyper-V.