password conflict Social theme

When you signup in the BP social theme you can fill in your password. (Standard feature of this theme.. no signup-password plugin installed)
I thought this was solved but it still sends an automatic generated password with the welcome email.
Also without any Mu plugins installed.

I've got the site not live yet, but I'm sure this might give some confusion to the users.

Is this a known issue? And how can I solve this?