Registration plugin stops working after v3.7

[malmazan]

Hi all :

I had a simple plugin that would automatically capitalize usernames at registration (I require registration with a full name).

This has stopped working when going from 3.6.8 to 3.7.0

It is a really simple piece of code that uses the userdata_presave hook

$username = ucwords(strtolower($this->fetch_field('username')));
$username_raw = $username;

Does anybody know why it does not work now and/or what I can do to fix it?