Are you sure you saved your terrain in the size 512 512?
To get rid of the portals at cape just go in the map maker and load the map you want removed. Then, see the little checked box? Click it and it should uncheck, then save.
If you want to remove it completely just go in Feralheart>media>terrains and click on the folder that has your map's display name. Delete it.
That's all I know how to help ya now. Hope this helped.~