I'm a little new to this, just getting my feet wet.. so I'm not sure if this will help or not.
I get that error on occasion when I rework a machine that may have been on the domain under a different name (not 100% sure if this is the cause). Clearing our switches ARP table sometimes helps get me past it.
I hope that this information is helpful, if not.. the website is "windows-noob" so you can't get too upset with me.