Hi,
Maybe it would be good to provide a visual feedback after pressing enter or clicking the 'login' button for the user portal. Logging in takes a few seconds (running astaro under vmware, anyway..) and I have seen some users press enter, and then take the mouse to also click the button, assuming that simply pressing enter was not enough.
Maybe the username/password could become grey, when it starts logging in? (to indicate: "please hold on, I'm logging in...") (or something similar to to the astaro webadmin: a popup, saying "please wait, logging in"")