pk told me I had two updates. When I clicked update, I got a 'failed to update system' dialog with the following details...
Method "UpdateSystem" with signature "" on interface "org.freedesktop.PackageKit.Transaction" doesn't exist
ah, this is possibly because I have the f9 livna repo enabled on f10.
I just had an encounter with a similar message box:
Failed to install package
Unknown error. Please refer to the detailed report and report in bugzilla
Method "UpdateSystem" with signature "as" on interface
"org.freedesktop.PackageKit.Transaction" doesn't exist
*** Bug 466516 has been marked as a duplicate of this bug. ***
AFAICT, this issue somehow is connected to PackageKit's authentication (usermode?).
It only occurs, after having been asked to authenticate as "root" and seemingly having successfully authenticated as root.
I.e. when 1st selecting to add/remove packages and 2nd authenicate, then this error appears.
When returning to the "add/remove packages" dialog, after such error, retrying to process the requested steps (pressing "Apply" again), appear to work.
*** This bug has been marked as a duplicate of bug 469950 ***