RAMPS D8 and D9 mixed up

After the accident with the first RAMPS I bought new one and it arrived couple days ago. I moved jumpers, steppers and wiring to it from the old one but I could not get it to work properly. The fan at D9 and heat bed at D8 were somehow bridged and worked at the same time. I didn't see any obvious soldering mistake on the back side of the board so I was quite puzzled. Some searches on the RepRap forum gave me a hint and the problem turned out to be MOSFET heat sinks touching and messing up the logic. Only a little bending was required and now the printer is operational again.