Bypassing form validation during user registration.

When I check "Show this node profile during user registration." option in properties of my user-specific node additional forms appear during registration process but there is no validation of them. I can leave required fields empty without any notification and receive welcome message...

Later then when I try to edit this node validation works properly and I cannot go forward without selecting required radios/checkboxes. So, I assume that it's a bug of bypassing validation when we glue some node with registration.