I use HRD Sat., SatPC32 and Amsat Droid. SatPC32 and Amsat Droid agree on position of FM birds, HRD shows some birds 30 min. earlier than expected. Mainly, AO-91 and AO-85. Anyone else noticed this tracking error ? I have "poured" thru ALL HRD's settings, reloaded keps, etc. Nothing seems to correct this tracking anomaly. Grrrrr. Best to All - WB1FXX