[cisco-voip] Get Update Failed error when saving VG224 with new MAC address

[Erick Bergquist]

Anyone seen this before?  Call Manager version 5.1.1.3126-1

Error Message	Update failed. [491] The specified name has invalid
characters or is not formatted correctly for this device type.

The MAC address field on the page saids use last 10 characters, which
I was doing. No spaces, etc.
I changed a character in the middle of the old MAC address from E to B
and it also failed to update.

Had a VG224 get a bad port, and RMA'd and tried to update the MAC
Address field on the gateway configuration page but it fails to
update.

I was able to add a new gateway with the new MAC address just fine,
but had to reconfigure all the ports and associate the DNs to them.