I looked around in the manual and may have missed it but today I was in the air and was getting the steady single flash of the LEDs indicating I was in GPS mode. I noticed that for a few minutes every once and a while it would blink green twice quickly and then go back to the single green flash. I switched to GS to make sure it was still reading GPS mode and it was the whole time. I thought I noticed this happening as I accelorated although may have been coincidence. the I have also noticed lately that even when it flashes green indicating I am in GPS mode AND the GS confirms it is in fact in GPS mode that when I take off there is a few minutes of drift even though everything tells me its in GPS and not ATTI. After a minute or two it will stabalize and hold its position but it almost got me in trouble when it started to drift and I wasnt expecting it to.