I've created a login on a wiki via OpenID (using MyOpenID). Now when I go to Special:ChangeEmail it doesn't accept any password and if I go to Special:PasswordReset it can't because no email is set. I've tried ticking all in preferences for updating from OpenID every time I log in but that hasn't helped. MediaWiki 1.19.2 and OpenID 1.004 20120427.
Topic on Extension talk:OpenID
I managed to work around the problem at Special:Preferences#mw-prefsection-openid, by associating a StackExchange OpenID and setting the option to update the password at login. I couldn't get the same to work with MyOpenID.
It's not my wiki, so I'm unable to upgrade the OpenID extension.
Thanks for reporting. The way you decribed is also what I would recommend, but is may not be always possible to add further OpenID.