Email Activation not including complete URL

[Kaisan]

My database crashed a few days ago after the language table was corrupted. I fixed it by replacing the table with a 24 hour old backup I had and everything worked fine. It's a couple of days later now and for some reason, all new members are sent activation codes like this:

To complete your registration, please visit this URL:
/register.php?a=act&u=8454&i=1d7916cb4e1f751e6d791ed8eff10825ff27ab26

What's weird is, it's only today that this problem started. I didn't change any settings or mess with the database anymore. I checked that my sites URL was included in the admin cp and it is.

Does anyone know what could be causing the problem?