CBS Early Show Staffers: Watch Your BacksHow is it humanly possible for the CBS Early Show to be so dysfunctional? And so early in the morning, at that? The show has been a nest of infighting for months, since the times of deposed mean boss Shelley Ross. Now, we hear that more scheming and devious machinations are underway. A tipster says that Zev Shalev, who was named a senior producer for the show in March (and who CBS execs are said to want to take over permanently as the show's top producer), may be in the crosshairs of Michael Rosen, another senior producer who was once described to us as "a tyrant to the staff." Laurye Blackford, a departing senior producer and "mean girl," may also be involved. Of course, anyone who has survived at the show through all of its internal turbulence must be presumed to be an expert Machiavellian corporate backstabber. Beware, CBS staffers! Do you have any more info on the Early Show's drama? Email us, please.