KDE monitor control settings loose memory 12.1 - 64 standard repos

Following problem.
I have a laptop (Lenovo X201) on a dockingstation (Ultrabase). It is branched via a VGA to an external Samsung Monitor SyncMaster 740N.
When I start up the system, in KDE, both screens are seen correctly as functional, but the resolution settings are “uniformized” to a 1024x768 resolution on both screens.
I did therefore set the correct (IMO) setting that are also automaticly detected:
1280x800 (automatic) on LVDS1 (and that is the Lenovo 16:9 screen of the notebook with 60,2 Hz).
1280x1024 (automatic) on VGA1 (and this is the Lenovo 4:5 screen with 60,0 Hz).
Both are set to “do not unify the videoexits, no rotation, position absolute”.
This gives me a screen that is on the Samsung slightly larger versus the lower part then on the notebook. I am perfectly fine with it, as it does not change the position of the plasmoids on the laptop desktop, once the laptop is detached.
But this setting is subject to amnesia. Although I did set it as predifined and safed it, everytime I boot the machine with the ultrabase attached, the setting returns to the 1024x768 unified (although unified is deselected) and I have to reset manually the screen.
It is not that I cannot live with it, but it is annoying. So I wondered whether there is somewhere else a setting that would preserve the dual screen setup I described. Just to avoid the continuous amnesia.
Thank you.