There is a easy and safe way to change language keys for the modules. Go into modules\boonex\modulename\install\langs and edit the en.php file.

Then go into admin and recompile for whatever module you changed and your done. Its then is safe to recompile anytime you need to. This is actually what happens when a module language is recompiled. It reads the contents of the file in the modules install folder which is what caused your over write problem.

However when upgrading to a new version of see more dolphin, those language files get over written by any that have been updated, so you should keep a backup of them.