install-updates button fails to operate unless check button pressed first
Binary package hint: update-manager
I frequently find that when I come back to a machine in which the Update Manager has popped up a window, presumably some time ago, clicking on the install-updates button has no effect until the check button is pressed first. Upon pressing the Check button, I'm prompted for a password, and the check-for-updates runs, usually coming up with the same set of updates as before, then pressing the install-updates button works (and no password is asked again).
Further, it seems unusual that check-for-updates requires a password, since Update Manager just pops up and runs this function all by itself without a password - why would a password be necessary to bring the check up to date?