As most Linux users do, I eventually resorted to the Terminal to get this fixed. Here are the steps I followed:
- Configure your settings as you would like them to be permanently using the System Settings UI
- Go to Terminal
- Get your current display settings: "xrandr"
- Make note of the graphics interfaces listed as "connected" and their positioning, resolution, refresh rates
Hint: you can extract similar information from ~/.kde/share/config/krandrrc
- Go to /etc/X11
- Create a new shell script (e.g. "sudo nano fixKDEdisplay.sh")
- Enter the details as you would like them to be set, based on your current configuration in (3)
- In our example:### For DisplayPort card (ATI Radeon H6450)xrandr --output DVI-0 --pos 0x0 --mode 1920x1200 --refresh 60.0xrandr --output DisplayPort-0 --pos 1920x0 --mode 1920x1200 --refresh 60.0xrandr --output DVI-0 --primary
Hint: if you used the krandrrc file above, replace the \n with new lines instead
- Save and quit
- Make the script executable (e.g. "sudo chmod 755 fixKDEdisplay.sh")
- Now make sure this script runs on every startup by going to System Settings --> Startup and Shutdown
- "reboot" to make sure
- Problem solved!