Good call Tommy! 
Donna655, I can't tell you why the Demo cause the older version to report "Reg Code" not matching. The Demo doesn't have any security checking in it, so there is no way it can change the prior version.
However... your post is clear that something changed. I'll have our programmers look into this. A demo should not change an installed verison.
Post here if you have any more problems, or Tommy's suggestion doesn't fix it.