kmix volume display acts strange

Hello, after installing kde 4.6 - no previous kde installed in my fedora system - I noticed that the volume OSD acts erratically. For example, I use my keyboard's volume control key and the volume OSD sometimes appers, sometimes not, sometimes I turn the volume up and then down and the volume OSD either follows the change or slowly or does the opposite!!! In any case the real sound level and kmix icon on taskbar are properly adjusted/displayed only the OSD is wrong. I have also removed the config files from ~/.kde/share/config but the problem remains. Any ideas? thanks George