I just installed Openfire and the Registration plugin on Debian 5.0 Lenny.
When I use the Registration Web Sign-up form, and try to create an account with a username that already exists, the browser shows error message:
???registration.sign.up.user_exist???
This is because the corresponding property has the wrong name (registration.sign.up.create.user_exist) in file:
/usr/share/openfire/plugins/registration/i18n/registration_i18n.properties
You can fix this by renaming that property to registration.sign.up.user_exist