If you are using Windows, look in (My) Documents > My Games > Beyond the Sword and you will see a CustomAssets folder. Look at the Properties and it should show 0 bytes, 0 files (there should be a complex tree of subfolders, but nothing in any of them).
If there is, then back up or delete those files.
(It's a way that you can change parts of the game just for yourself. For example, I sometimes change the names of 'Protestant Monastery', 'Islamic Temple' and 'Islamic Mosque' to 'Protestant Seminary', 'Islamic Mosque', and 'Islamic Grand Mosque' respectively)