I think i might know the problem with my maps, chris jerry who is a friend of mine told me about the land however im not sure yet about if he is right so there might be a chance to make my maps some point...
Thats not your fault directly but there are some things you can do to reduce the problem.
Loading and saveing the same xxx.lnd into any of the editors causes minor problems the more you load and save the worse it gets .
If you realy have to create your own land then try to do it in a single edit and save in B&W Surveyor. As always the long zoom outs won't be 100% but the land at playing distance should look good with no tileing.