I am using 8.10. I seldom get a notification of available updates from
Update Manager. Yet, if I run "Check", Update Manager usually has some
updates for me.
I am guessing that I don't have all the sources that I need in Software
Sources. Is this my problem, and if so how can I determine which
source(s) to add? I would ask Google, but I don't know how to structure
a short query.