I am running Kubuntu 13.10 daily builds. After applying today's update (which seemed to include an updated Kernel), I noticed the orange arrow in my panel that indicated a restart was required. I clicked on it, and the orange arrow went away, but it did not restart. Reproducible: Always No big deal, I just manually re-started.
This is not a bug in Muon. For today's updates, I used: sudo apt-get update sudo apt-get ugrade and saw the same behavior. That is the orange arrow appeared, I clicked on it, and it disappeared without re-starting my virtual machine. If you know what component controls the orange arrow, please re-assign the bug.
It worked for me for the first time today (Kubuntu 14.04 Daily Build with today's updates).