User blocked direct after order & registration

[betterlead]

I am starting to panic! Well not really, but I have searched for a solution to this problem but can't find any.

All my customer´s accounts (Except them paying with Klarna) are immediately blocked after ordering/registering. Everything looks ok in the configuration, but this always happens. When the visitor wants to buy something for the second time or just check the status of her/his order without having the link from the order confirmation E-mail, they simply cannot do login. This is of course very, very bad indeed. A returning customer should really not be blocked out.
I suspect this is a bug. Is the problem known? Probably yes. Then, what is the solution, if there is any?

J2.5.28
VM2.6.14

http://tingshop.com

[Milbo]

which payment do you else use?
maybe there is the problem?

[betterlead]

Klarna (iframe)
Paypal
And the third is for companies - standard VM, OPC(?) I think.

[betterlead]

This is probably not much of help, this screen shot, but anyway...
Tell me if it would help if you got any more info.