I have an HR20 which had it's hard drive fail a couple of years back. I have been running successfully with a Wd 1T drive since then. Recently I have noticed I will turn my tv on and discover my Hr20 is back to using the internal drive but having freeze ups(the original problem). My solution is to unplug the external drive's power and the Hr20 power and then fire it all back up, giving the hard drive a 30 second head start. It always comes back up and works. In a day or so, I find the HR20 using the internal drive again an so I repeat the process. Tonight I tried just rebooting the HR20 and got an error75-542. I then rebooted both devices. After watching about 45 minutes, the HR 20 suddenly told me it was restarting. I let it and it came back up on the internal drive. Can any one tell me which device is likely to be my culprit?