Please help on email name!

[محروم.كوم]

finished setting up vbulletin* adding modules* add-ons..
everything fine* so I tried to register my first user to check out the translation and everything..

mail recieved properly and activation link working flawlessy...
only problem* I have an underscore "_" instead of any kind of name at the side of the email address* here is how it looks like in the hotmail inbox.
From _
how* where do I change that underscore?
thanks a lot!

Attached Images email.jpg‎ (10.0 KB) __DEFINE_LIKE_SHARE__