Well the HD-FOX works fine and I can watch the recordings I made on the USB-connected SATA drive in a docking station, and/or use the composite video to record on a PC using a capture card. It just so happens that there are some recordings that I would have liked to have kept by archiving on a PC, a la HDR-FOX.
I haven't gone into the possibilities of using the CF as there seems no way for the HD-FOX to recognise 2 USB drives. The docking station has a pass through but plugging a stick in doesn't get picked up.
The unit should be able to see two USB drives: a simple USB hub will do the trick. You will have to power at least one of the drives though as the USB port won't provide enough power for two.
To clarify, the drive that has the recordings on it is formatted in ext3 format and is the one used previously as the recording drive on the HD-FOX? If so the custom firmware is, as stated in above posts, the easiest way to get copies of your files and you only need one drive to decrypt. Summary below:
With just the one hard drive connected by USB, this drive should be mounted as 'drive1' (should be automatic) and presumably the recordings are in /drive1/Video.
Create a new folder e.g. /drive1/Recordings.
Install the custom firmware, download the full web interface and install the packages auto-unprotect and boot-HDR. Auto-unprotect will scan the 'Video' folder and remove the protection flags ('Enc' flags) from any high def. recordings.
Boot the unit into HDR mode: read up about boot-HDR on the wiki and in Black Hole's guides. The box will now be running the HDR-FOX software. The external USB drive will now appear to be mounted twice: as both the internal drive (the 'Video' folder will be mounted as /media/My Video) and as a USB device (drive1).
With the remote control handset, copy your programmes from '/media/My Video' to '/drive1/Recordings'. The recordings will be copied and decrypted in the process. When complete reboot.
The contents of /drive1/Recordings will be decrypted and playable on other devices such as a HDR-FOX or a PC.