Sensor DHT22 on modul A16

[twostar]

I've just checked it and it has a 10kΩ pullup on the sensor, could this be what's causing the problem?  That is, if both the sensor and the A16 have pullups you'd have a much lower resistance... but then some sources recommend a 4.7kΩ pullup which is what would be in effect if both ends have 10kΩ pullups so it should still work.