Has anyone run into this dhcpsrvr error code=19?

"dhcpdecline packet has been received from client <00:1b:77:37:8e:12>"

The error message states ".. Error Code=19 after dhcpsrvr cache has been queried for client <00:1b:77:37:8e:12>

the client's hwd address being specified is a Intel PRO/Wireless 3945ABG network card in a dell latitude d520 thank is trying to renew it's ip address.

Thank you for the help