Well that doesn't help me out any...
Maybe in the future your protection should check the version, if that's possible. When you make significant changes to the engine, people may give it another look. I wouldn't think it would be that hard to check if the version trying to be installed is greater than the current (or previously) installed version.
In my case I'm building a new system in the next few weeks, so it's not that big of an issue. But when adding something as large as supporting a new language, could be useful...
Just my .2...