Paint layer not loading in full size

[Anonymous]

Newbie 101 question. I started with a base 4096x4096. Displaced it with the same size heightmap, and now I've been trying to load my 4096 sized diffuse map, but my paint layer is cutting off short to one side. I also dropped a new blank paint layer to test paint some white on it, and the same sizing short happens. The picture I've attached shows what is loading. Any ideas?

[Anonymous]

Okay, after applying my texture after loading in my plane, the texture on the paint layer was full size. When I tried to subdivide, it shrank when the model went past level three to 1024 polygons. I had started with basic 8 poly square which must have been the problem? I created a high poly plane as my base and that seems to have solved the problem.