I just registered a test user so I could replicate the issue and I noticed this difference in the subject lines:
[Girls Can' ;t WHAT?] Activate Your Account (intentional space left in to demonstrate the error)
[Girls Can’t WHAT?] New User Registration
The new user registration notice is correct in the subject line (the sender is still displaying wrong, although it used to just say ‘WordPress’ for the sender name.)
So is this a buddypress issue or a wordpress issue?
I tried the anti-slash and double anti-slash…still nothing. The emails are picking up this string from the general options “blog title”. I don’t know of any other way to make it work.