Time Warner Cable won’t pull CBS-owned stations in 13 markets off its systems until at least Monday under an extended negotiations deadline, but cable viewers of the CBS affiliate in Omaha, Neb., weren’t so lucky. That station, along with NBC affiliates in Milwaukee, Wisc., Green Bay, Wisc., and Palm Springs, Calif, were dropped by Time Warner early Thursday morning as a result of a separate retransmission feed dispute with the stations’ owner, Journal Broadcast Group.