Title pretty much says it all, I encountered this problem with Morrowind CS set aswell, heres how it goes.

Ok so ive just created a landmass (Island) and ive begun to texture it with grass, but on a certain point of the island there is a sand texture that i cant put grass on ive tried everything and searched on the internet for a solution but with no luck

This problem is annoying me as i cannot texture the whole of the island, and this is a main part of the island. that i wish to place something on.

any help will be appreciated.

This should be moved to Morrowind's CS forum.

This problem is occuring with the Oblivon CS set i merely mentioned that i had the same problem when i use to use the Morrowind CS

Have you got an object selected while you are trying to texture the land?

If so, then the cells adjacent to the cell that the selected object is in won't load, regardless of where the camera is positioned, and it forms a boundary of sorts where it won't let you texture. Deselecting the object and letting the adjacent cells load should allow you to texture the land.

If not, then I'm not sure what's wrong, sorry.

yea that wasent the problem, im unable to texture a certain area, if anyone needs a SS i can happily provide one.

It's probably due to having too many textures in a cell (or rather cell-quad). These areas should be straight borders either along cell boundaries, or exactly in the middle of a cell. If so, move to that cell and press "I" then replace textures with a low coverage % with ones with a higher %. Each cell can have about 8-9 textures. Alternatively, you can paint over the entire cell in a texture that is at 100% opacity to clear out any remnant textures quickly. This problem usually happens when you're either trying to find the best texture for that cell and don't clean up afterward, when you have multiple textures in that cell with low opacity, or when you're combining things like roads with other patches of terrain that need layering.