hmm check the file lengths of edited and old files. If they are very different (more than just a number of characters you wrote), then you have saved it in a different encoding. RTW is very sensitive to that. Also, I assume you've properly edited the enum and text/export_building.txt files? Remember to add a 'xxx_name' section to these files.
But these bugs should be caught by -show_err... and there really is nothing in the engine that could prevent you from having multiple buildings called 'temple' in game, as long as they have all unique names in the code...