A new version, 7.77.2, was uploaded under the same URL. The terrain stitching problem is now fixed.

Vlau: check if the file wwmp2wmb.exe exists in your Gamestudio folder, with a size of 716 KB. If it exists but does not start, some system DLLs of your PC are possibly damaged. This could be fixed by installing XP again. Also, run a virus check, just in case.