the lone ranger:
you can copy the recorded movies. It is a bit involved, tho, and remember they are digitally protected are only playable in another DVR, not say on your computer.
The SA boxes format the disks in a Linux format.
So to do it you have to remove the HD from the DVR ( without damaging the "void" sticker on the inside, attach the drive to a computer running Linux and copy the files. You then copy them back to the new HD and replace it in the new DVR.
Do a google search for - cloning internal HD SA8300 and you will find the instructions on the Rogers Cable forum