This desktop (Dell Optiplex 280 + RAM + SSD) is used by my wife and me. Well mostly me but sometimes I give her opportunity

I suppose that this is connected with plasma-desktop but restarting it doesn't help. Probably Intel driver is involved also. I tried FrameBuffer driver with the same results. I also tried to change driver to vesa to test that but got "no screens found" error.
Few details from Xorg log when I test new configuration in mcc.
- Code: Select all
Screen 0 deleted because of no matching config section.
(II) UnloadModule: "vesa"
(EE) Device(s) detected, but none match those in the config file.
Fatal server error:
no screens found
I would like to get more and clear informations about this issue before I report a bug.
Any help is appreciated!
EDIT: Small clarification about stored KDE session.
EDIT 2: I installed Mageia 3 32bit clean from Mageia-3-i586-DVD.iso