I read in the datasheet of the BMP085 barometer used in the APM that its sensitive to light (and probably the airflow generated by wind and props) which influences the accuracy.
Was wondering if anybody covered it and with what material as it still needs to be able to sense the ambient airpressure accuratly.
Found an old electret condenser mic in my pieces box. The little sticker protecting the mic fits just nicely onto the sensor.
Good to hear it makes a difference. Maybe good idea to put this into the WIKI.