I replaced the AcomData drive with a 500gb Maxtor and now things seem to be working, although there were some startup problems. When I first attached the drive it acted just like the Acom with the "unsupported device" message, and wasn't recognized. I then did a soft reboot while the Maxtor was attached and it came up saying that I had a USB drive attached that needed formatting. After the formatting was finished, the 622 restarted, but hung at the 0 of 5 phase of the acquiring satellites screen. I had to unplug the drive, do another soft reboot, then plug in the drive to get it to work. It seemed that it would not boot while the drive was attached. Once it did reboot, I plugged in the drive and everything seemed to work normally. I transferred a 6 GB program in about 28 minutes. I am now trying a bigger transfer of about 23GB. One nice feature is that you can play programs directly from the attached drive and do not need to transfer them back to the internal drive for viewing. Also, when you transfer a program from the internal disk to the USB drive it is automatically deleted from the internal disk. I don't know if it's possible to copy a program to the USB drive and still keep it on the internal disk. I'm still concerned about the booting issue since the 622 reboots itself periodically, like when it gets a software update. If it can't reboot on it's own with the USB drive attached, it may miss timers until I can get to it and detach the drive. Otherwise I will have to make sure that the USB drive is not attached when the 622 is unattended. I'll try the reboot with the drive plugged in again once there is some data on the drive to see if it is still a problem. Has anyone else run into these issues?