Over the past year or so, I've noticed that my 396XT will suddenly stop receiving a local 700 mHz, 4-site ASTRO trunked system. The RSSI will flash like it's receiving a data channel but the area on the screen where the data channel is displayed will be blank. It's just not one site, but all of them. Meanwhile, the two other scanners that I have monitoring the same system will be receiving it just fine. This only happens when the 396XT is connected to the factory-supplied AC power adapter. To rectify the problem, I have to disconnect the scanner from the power supply and then reconnect it. Can anyone tell me what might be going on here?