The two drives became /dev/sdb and /dev/sdf in Knoppix 5.1.1. When completed the EOF line and Summary are displayed before returning to the "[email protected]:~#" prompt.
Slow or incomplete POST with the HDD sometimes being detected in the BIOS setup and sometimes not.Headed for bed but thought there was nothing to lose by putting the HDD into a ziplock plastic bag into the freezer. We were very surprised that the "freezer trick" worked, since it has been a dismal failure in the past.In the morning the HDD was reattached and the Knoppix CD (still in its drawer) just booted straight up in sprightly fashion after having whizzed through the POST screens. We were absolutely delighted with dd_rescue and can see we will be using it in place of dd in the future as we grow in familiarity with it.In the forums where people have discussed this problem (for example here, here, and here), there have been various theories that have been floated and discarded.
At first I thought it only happened when I was clicking on files stored on a network shared folder instead of my local hard drive, as suggested in a few forum posts.If things seem a bit hard to comprehend perhaps read a few of the tips on our Back-up using Knoppix page.