I have two Premiere Xl4's both using a Motorola tuning adapter. I can tune all channels including SDV on both, however I have the same issues as many in that suggestions will non populate with TA's attached so I'm using a timer to turn them off at night until TiVo sorts this out. That said, I notice that when I try to test channels from the diagnostics utilities from within TiVo, it doesn't see any channels, the same is true when trying to get a signal level. The only way the TiVo seems to see channels is under the tuning adapter diagnostics. Is anyone else who's using a TA having the same experience?