I've read many complaints against KPackageKit on this forum.
But I need some software, that would notify me about new security and bug fixes, so that I can choose what to install manually.
There was not so bad notifier in KDE 4 in F9.
But now I use F11 and it's KPackageKit is very strange.
If I run it manually it finds all updates and installs what I said to him.
I've made some changes in its settings: "check for updates: hourly", "automatically install: none", "notify me when new updates are available".
After I install updates as stated above, KPackageKit's tray icon appears every hour to check for new updates. It does so today, tomorrow and maybe some days further.
But then it ceases to make such checks. Just nothing happens. It doesn't work and I don't know if there are any new updates available.
So when I feel that there were no updates for too long time, I run "yum update" and see many new ones.
I don't close my KDE session for many days. It's always open.