Can you check to be sure that all the files from zp-core/js have been updated on your installation? The options page is normally tabbed, and only one tab is visible. In your case it should be the #tab_admin. That would be the form that allows you to enter your user name and password. In your case, nothing is visible, So it would seem something is going wrong with the java script that manages the tabs.
Also check your CGI error log to see if anything has been recorded there.