The card really is poorly designed. As I already said:
Originally Posted by Vas Crabb
Similarly, the card will reject any active (rising) acknowledge edge while strobe is active, so if the printer responds to the negative edge before the card sends it high again, it miss it and wait forever.
They must have never tested it with a printer that could acknowledge a byte in less than one microsecond. Actually, I doubt they tested it much at all given the other issues.