Transfer slowness in Windows 2008 servers

I've got a weird situation:

Have two servers running Windows Server 2008 SP2, 32 bits. They're in the same switch, when I transfer any file from one server to the other one the window "Preparing to copy" pops up and it takes an eternity to "calculate" and nothing happens, the copy is not done.

The curious thing here is if I do the same but from/to a server running Windows Server 2003 to any of my servers running Windows Server 2008 SP2, the copy takes place without any delay. I already used a crossover cable between of these 2008 servers and nothing!.

Any idea what's happening ? Any hotfix ? Workaround ?

Regards,

RJC