annoying dialog appears "Monitor setup has changed" kde4

Not a bug, that is the expected behavior

it is a bug!

it appears during normal work, not while plugging external screens

I have noticed the same bug on my computer after upgrading from Hardy Heron to Intrepid Ibex. It is really annoying and it happens randomly (often twice in quick succession). Please tell me, if you need any files or information on my system.

I can confirm this bug

I also see this very frequently for no apparent reason. There always appear two windows in very quick succession. The first is (incorrectly) reporting a new monitor connection event, and the second is (also incorrectly) reporting a disconnection event. The dialog is either "A new monitor output has been connected." or "A monitor output has been disconnected."

This is on a brand new installation of Kubuntu 8.10 on a Dell Latitude E5500. The frequency of the occurrences seems to have decreased after I did an update (of 85 packages that I didn't pay particularly close attention to) right after initial installation, but it still happens every 10-15 minutes. While I was waiting for it to happen just now to gather data for this comment, nothing happened for about five minutes, then six windows (three connections, three disconnections) popped up over the span of about four seconds.

When everything was sitting happily at idle, xrandr's output looks like this:
eangell@thorin:~$ xrandr
Screen 0: minimum 320 x 200, current 1440 x 900, maximum 1440 x 1440
VGA disconnected (normal left inverted right x axis y axis)
LVDS connected 1440x900+0+0 (normal left inverted right x axis y axis) 331mm x 207mm
   1440x900 59.9*+
   1360x768 59.8
   1152x864 60.0
   1024x768 60.0
   800x600 60.3
   640x480 59.9
HDMI-1 disconnected (normal left inverted right x axis y axis)
HDMI-2 disconnected (normal left inverted right x axis y axis)
TV disconnected (normal left inverted right x axis y axis)
eangell@thorin:~$

Once the crazy started happening, I managed to run xrandr a few times. Some were normal and some were a bit nuts (but all identical). The "connected" and "disconnected" dialogs appear so quickly (and steal focus, and seem to bog down the machine momentarily) that I'm not sure what the exact state was when I managed to obtain these samples. The "nuts" version looks like this:
eangell@thorin:~$ xrandr
Screen 0: minimum 320 x 200, current 1440 x 900, maximum 1440 x 1440
VGA disconnected (normal left inverted right x axis y axis)
LVDS connected 1440x900+0+0 (normal left inverted right x axis y axis) 331mm x 207mm
   1440x900 59.9*+
   1360x768 59.8
   1152x864 60.0
   1024x768 60.0
   800x600 60.3
   640x480 59.9
HDMI-1 disconnected (normal left inverted right x axis y axis)
HDMI-2 disconnected (normal left inverted right x axis y axis)
TV disconnected (normal left inverted right x axis y axis)
  1024x768 (0xa7) 26.9MHz
        h: width 1024 start 1025 end 1088 total 1120 skew 0 clock 24.0KHz
        v: height 768 start 769 end 800 total 801 clock 30.0Hz
  800x600 (0xa8) 17.0...

Sorry, I retract my offer to provide more info on request. Too much stuff is broken in KDE4 (unrelated to this) and I can't get any work done, so it's back to GNOME for me.

However, given the info that I provided, specifically the weirdness in xrandr, I suspect this particular issue is one with either the intel module or the X server itself, and it is only reported here as a KDE bug because KDE offers a handy popup on display configuration changes (and the symptom, not the problem, gets reported).

If other people who have reported this bug or anyone else suffering from it could identify their graphics chipset and corresponding X driver (see the part of my comment where I determine that I have an Intel GM45), that could potentially help narrow this down to an intel driver issue.

But either way, I'm afraid I'm out of help on this issue since I'm bailing on KDE completely. Good luck!

This has been fixed in the KDE 4.2 beta packages. We were using an xrandr detection patch from OpenSuse that caused this problem. The patch has been removed in KDE 4.2 in favor of better multiscreen-handling software, kephal.