I am having the same problem. I usually just end up killing plasma-desktop and restarting it. This probably happens 10x throughout the day. I have not seen the same problem on my other desktop. This problem started when I upgraded to KDE 4.3.0.
$ lspci |grep VGA
01:00.0 VGA compatible controller: ATI Technologies Inc Mobility Radeon HD 3400 Series
I am having the same problem. I usually just end up killing plasma-desktop and restarting it. This probably happens 10x throughout the day. I have not seen the same problem on my other desktop. This problem started when I upgraded to KDE 4.3.0.
$ lspci |grep VGA
01:00.0 VGA compatible controller: ATI Technologies Inc Mobility Radeon HD 3400 Series