Recently we have been experiencing some problems with DEFAULT_POP_QUOTA and OWNEDIP tokens. Our skin makes use of these tokens to create direct links to create email and ftp accounts out of pop.html and ftp.html, and the values for these tokens are none, getting these links...
Surely is a bug with your login install. The password field must contains the button you lack.
Can you check if the folder /usr/local/directadmin/data/templates/login_images contains all the images in [cyberadmin_folder]/login/img?