Buffetted as we often are by TV spinmeisters, we are encouraged by candor. Two research chiefs, Turner's Bob Sieber and CBS' David Poltrack, have conflicting analyses of how broadcast and cable performed this summer. But the difference is not what you might expect. Both agree that broadcast and cable showed encouraging gains over the summer, with broadcast reversing its traditional summer slide and cable still making strong gains. But the broadcast numbers in Sieber's report are a little better than the ones in Poltrack's, while the CBS executive's cable numbers are a tad higher than Sieber's.