- Intel(R) Core(TM)2 Quad CPU Q9400 @ 2.66GHz
- 4GB RAM
- Graphics: Intel® G45/G43
I believe that the problem was caused by flash. I installed the Flashblock extension in Chrome and also turned off the 3D accelarated unity desktop of Ubuntu by installing gnome-session-fallback and choosing it at next logon.
The combined effect is amazing, the computer is blazing fast again...
sudo apt-get install gnome-session-fallback
One more thing:
The panels in the fallback mode can only be edited by pressing alt + super + right click...
The whole problem was caused by the lack of enough ram. Just adding 1GB to the previous 4 that I had eliminated all problems. According to 'top' I use about 4.7GB when using virtualbox.