WordPress MU

I am finding it impossible to upgrade from 2.5 to 2.6. My hosting is on Go Daddy - all the sites on Network Solutions upgraded without a problem. But when I upgrade to 2.6 on the Go Daddy hosting account everything seems to go well until I have to log back in after the installation. The old password does not work and I request a new password. That doesn't work either - so I have had to go back to 2.5 just to get the site to display. Any ideas? Thanks, Chief

Please don't multi post the same thing over and over again. Just like in real life, repeating yourself before giving someone else a chance to respond is considered rude.