HI DAN,
I HAVE ALWAYS FOUND THIS PROBLEM RELATES TO THE MAIN BOX SURROUNDING THE MAP.
THIS BEING A FAIRLY REGULAR OCCURRENCE WITH MY MAPS ANYWAY.
TO CURE THIS I HAVE FOUND IF YOU LOOK AT YOUR MAP BOX / SKY BOX (HOLLOWED CUBE) MOVE THE FACES
SO THEY ARE OVERLAPPED BY SAY 50% ALL ROUND THE BOX, SOME YOU MAY EVEN PREFER TO MAKE FLUSH TO THE OUTER EDGES.
IN CASES LIKE THIS I USE THE EDGE MOVE TOOL IN PREFERENCE TO SCALING. BUT THAT WOULD BE TELLING THE MASTER HOW TO SUCK EGGS HA HA
HOPE THAT HELPS DAN.
BEST REGARDS.
PHILL.C.