Thanks for the reply


1)Not really a zero value but you do go from 79.59 to 80.00 becase there are 60 mins in a degree..But that should be easy enough..so from 80.07 you will hit 80.00 then 79.59 etc..
2) you are on the right track.. Thats what i first though and it seems to work fine for Longitude.. but Latitude I cant seem to get right maybe I have been looking at it to long and have become crosseyed!!

I'll drop you an Email with the map files might be easier if you see it