problems with coastlines

Hi all this may have been something i have done or added in the use of my sim setup but recently when flying over coast areas i see square edges ie no coast lines just blocks.To give a better discription its like the square tiles just end and dont do the coast line render at allAnyidea how i fix thisPS i have the uk vfr scenery installed and the coast in that work fine, just the other ones like the last night i flew PGUM to AYPY both coasts where blocksLooking forward to a quick fixYoursDarren [email protected]