Description of problem:
KDE does not properly handle multiple monitors when the external monitor, to which the desktop is "extended", is regularly removed and re-attached.

Laptop is a Thinkpad R61 with Intel integrated graphics.

Version-Release number of selected component (if applicable):
4.8.3-1.fc16.x86_64

How reproducible:
Always.

Steps to Reproduce:
1. Boot up and log in without external monitor attached.
2. Attach external monitor.
3. "Do you want to configure..." dialog pops up.
4. Click to configure new monitor.
5. Set right-of existing display, set default display to internal laptop display.
6. Click OK, accept configuration.
7. Verify desktop does extend to the external monitor.
8. Remove external monitor.
9. "Do you want to configure..." dialog appears again.
10. No settings available for external monitor, so only option is to click OK.
  
Actual results:
11. Mouse can still be moved off of the internal display into the screen area that was used by external monitor, even though the external display is detached and the configuration section for it is blanked out in the KDE display settings app.
12. Windows that were on the external monitor are not moved automatically to the internal display.

Expected results:
11. Display and mouse should be limited to only the internal monitor.
12. Windows on the external monitor should be automatically moved to the internal display.

Additional info:
Also, fairly regularly when reconnecting the external monitor, the desktop background is not applied to the external monitor.  Only a black background appears.

Using "xrandr --output LVDS1 --mode 1440x900 --output VGA1 --off" temporarily solves problem in step (11) listed above, until external monitor is used and then detached again.