The 1.4's to my knowledge are DIS, the problem you have, is you have clocks calibrated for DIS, (2 coils effectively, so obviously only sparking half the amount per coil, as theres 2 plugs run per coil), and your running a coil that operates all 4, therefore getting double the reading.

Check out the 1.4's incase im wrong but im sure everything in the MK5 range is DIS.

Can you post a picture up of the rev-counter itself (the PCB)