I opened up the cable and it's a Blackcat from diygadget.com.
It uses a Phillips 74LVC244AD chip to buffer but it seems it gets power from the parallel port.
The only schematic I could find for this Blackcat cable, which doesn't seem to be 100% accurate compared to the actual board, is this:
It seems like this cable uses 5v instead of 3.3v. Am I screwed or is there a way to make this work?
I guess you will already have tried to flash twice?
Failing that, I would:
connect the HDD to a Linux PC,
mount and rescue the data from the third partition,
delete the partititons and the partitioning scheme so the HDD is blank,
flash twice. The first round creates the partitions, the second copies the data to it.
Can't flash anymore because the LS is not seen by the PC in any way.