Context I have just installed Ubuntu 13.10 from an iso on my Asus X202E and everything was working fine so far. However I discovered that the icons from the tray (dropbox, wifi, keyboard, layout, battery and so on) are not working properly.
Problem Description Most of the time when I click on them they show the menu I am expecting to see but in some cases they just do not respond at all. I then move my pointer and re-click and everything is working well. This is not a big deal but I do not understand the cause of that and I would like to fix it for a smoother use.
Note that not all the icons are not working. The three most right buttons are ok: (shutdown-system settings-...) icon, sound options and clock-calendar icons.
I already ran
killall unity-panel-service but that did not solve the problem.
As proposed by Angel Salinas Huerta, I enabled the proposed updates in the software center and upgraded the system, but the problem is still there.
After wandering for some times on this site and some googling I hpoe to find some answers from you!