Being playing round with Lady heather 5.0 (really impressed) and my Jupiter-T receiver using Zodiac mode. But what is COFS. Can not find anything in the help or on the internet. Is it short for something? I did notice a couple bugs relating to rounding off. If I set the elevation mask to 10 degrees LH reports on the interface as 9.91? Not sure if the other parameters such as *DOPS are returning similar errors? Not sure if this is a bug, but I put the unit into survey mode for 2 hours and it keeps flipping between Navigation Mode and Survey mode/Self Survey with the screen flashing in between the switching. -=Bryan=-