Comment 15 for bug 416825

Brito: that is just a workaround. Another option is to open Keyring manager, select the login group and change the password manually (enter first you old login password and then new login password). After that the login group we'll be automatically open then you log in.

However a workaround isn't the point in here. The point is that changing you password brakes your Ubuntu installation from a normal users point of view, since it "suddently" starts to ask about some password and the user has no clue about why. This is still valid in Lucid, I saw it last week again while helping out a newbie.