If this has been addressed previously elsewhere, I couldn't find it. This is what's happening with me. I enter my inputs and create a drop chart and print it out. Using the same inputs, I create and print a field card. The wind drift results are different between the drop chart and the field card. I feel sure I've not been accidentally changing something. Also, sometimes the program has automatically changed my wind speed from 15 to 10 when I print it. Any ideas? Am I doing something wrong?