In OT kern subtable header, the format is the high byte of 'coverage' bit mask (bits 8-15), and the low byte (bits 0-7) is the actual coverage bits. In AAT kern, it's the opposite: the coverage flags are the high byte, whereas the subtable format is the low byte. Also adjusted the test data, and set coverage to 1 for OT kern subtable (which means the usual horizontal kerning).