I;m currently using myopenid. If I attempt to login with myopenid. I have to do the following. Click on the myloginid button (nothing visibly changes), then type in a username, then click "Log in". Based on past experiences with other sites, I expected to go directly on the myopenid auth procedure on one click, and then enter my username there. I think that if I am already logged into myopenid (ie there is a cookie), then I don't have to enter anything, which is preferable. Google and Yahoo are exceptions here - clicking on their icons takes you directly to their respective pages.
Issue #2632 wontfix