As far as I understand there are two different things possible:
1. Subcription for updates
2. Registration for contribution (get own profile, put comments or even blog entries depending on further Settings)
Some People that had already made a subcription to my blog reportet about Troubles with the Registration. It says, that this email adress is already being used and that they should enter another one. When I try to replicate the issue, my Problem is else. Everything works fine, but when I try to log in for the very first time - right after the activation by the activation link - it says "page not found". See attachment. .
Login Provider is joomla, but unfortunately I have no idea what the Problem could be.
Thanks a lot,
Chantal