1. Log in as user 2. Use Apper's taskbar icon to install proposed updates 3. At some point the installation aborts with message "aborted by user" 4. The real reason was a full root partition.
Fill a bug against your distribution PackageKit backend, it's the one which chooses what messages Apper should display.
Bug is now posted here: https://bugzilla.novell.com/show_bug.cgi?id=885909