Facebook connect: Logs members in as other members

I've had complaints from other members,  so I checked and sure enough it did for me as well. 

I click on the "Facebook Login" button and it logs me in as a seemingly random member. This one looks like it was the last person to create an account using FB Connect. 

It can login you as existing member only if email match.

Maybe there is some problem with email field, try to check if this field is populated properly.