I am running cc525.
Delivery address is the same as billing address - ticked box yes
When a customer registers and crates a password. Their account info in admin/customerlist shows a delivery address and a billing address -as expected
When a customer just enters their address without creating a password. Their account in the admin/ customer list shows the addresses have been duplicated i.e delivery address shown twice and billing address shown twice.
I have tried several test customers and it seems that every time the customer enters their details the next step they are taken to the address/details page, to check the shipping option chosen, the addresses are then duplicated.
I have one customer who had 4 copies of each address listed in their admin account details.i assume they just kept going backwards and forwards during the 'registration' phase. I have asked them how many times they had to enter their address and they have only entered it once.