Strange Hajo. Works for most. Check the directory location again?
I am just being thorough. I have had issues with file protection not allowing skins before. I had to manually change the properties for each file. What I would do is to compare the old file sizes to the new.
I replaced the entire settings folder with a copy of the settings folder from AHII. I backed the other up of course. But so far it seems to work fine.
It's not like if it blows up he can't uninstall the beta, get the full version and reinstall.