The 'Source' looks familiar
, usually that would be the resolution. There's something else goin' on then.
Try accessing the shared folder from the server this way=> Click on Start, run and type \\servername\sharedfoldername
you may also sub the servername with the server's IP Address.
Have you also try disconnecting the mapped network drive then reconnect to it?
How about logging in as a different User or as a Domain Admin from the problematic computer? Please see if you may duplicate the issue.
I assume that DHCP is coming from the server and it's using the Server's DNS Address.
Please let us know.