I have two panels configured in my KDE. The main panel at the bottom contains K Menu, desktop access, task bar, lock/logout, knetload, system tray and cklock. An additional panel (just called "Panel") at the top of the screen contains a knewsticker. This worked fine in 3.5.0.
When I start KDE 3.5.1, the flag indicating my keyboard layout (kxkb) is not in the system tray where it should be, but rather in the top left corner, next to my newsticker. It is obscuring the hide button of this panel.
When I quit kxkb (right klick and quit) and restart it, it appears in the system tray where it should be. The spacing of the panel where the icon was displayed before does not change however.
I can reproduce this bug by restarting X and KDE.
This should be filed at bugs.kde.org so the KDE developers can fix the issue.
Reported upstream, see URL.