How do I make KDE ***completely*** stop trying to draw backgrounds?
Most related questions seem to be how to put stuff onto the background
or the root. Not how to take it out. and most of those relate to the confusion of terms between X's 'root' window, and KDE's Desktop frame.

For the Strangest of reasons, I need to demonstrate an application running on both XP and Linux side by side.

The setup is mostly done. but there are a few display issues that some think spoil the show.

The remote Linux side is Suse10.1. (I didn't pick the Distro.)
Running KDE, largely because KDE can be dressed up with the best XP-like look and feel I can find. it looks fine, and acts right. (well... as right as it's gonna)
The Display ManagerKDM)is running on the Suse box.

The display server runs CygwinX on XP.
This because Cygwin's 'rootless' mode lets it just stay out of the way better than the commercial Xservers I've tried.
(I may have a problem though, with the old Xorg and no tranparency)

The connection is an ssh tunnel. (Cause XDMCP is a rathole I'd rather avoid.)

And to this point, all is well.

The Star of the show, is the app itself. So I don't want desktop icons laying over each other, so I turned of the KDE desktop through Kcontrol.

For those of you web searching like me, For KDE3.2 and later, Click the Kmenu icon (Bottom Left. down where the "Start" button would be). Select Control Center. Select Desktop. Select Behavior. and toggle 2 selection buttons labeled 'Allow programs in desktop window' and "Draw icons on desktop'.
Lo and behold, Kdesktop will kindly refrain from showing you your trash bucket.

Which, is the start of the problem.
Consensus seems to be that KDE puts up its own background window, and largely ignores the real 'root' window display plane.
(This is demonstrated by the fact that the color set by xsetroot on the display client is behind, and only shows up in between the Login, and Splash Screens, and sometimes briefly before the Desktop is drawn).

And, that Kdesktop draws this pseudo-root window. the 'Desktop'.

And that the Kcontrol desktop setting just tells Kdesktop not to do that.
However, Kdesktop is still running, and still displays 'something'.

Even after Kdesktop is killed, this false root is sometimes drawn.
The most noticable, is when an application window is grabbed or moved.
While the app window frame is grabbed, the focused window and background are drawn together. you will see either the last image that was set, or the Current KDE desktop background color including gradient settings. (NOT the xsetroot color).

I know Cygwin isn't drawing this because it's not the color the local display manager would use, even if it weren't 'rootless'.

So, How do I set the background displayed during grab events to NOTHING?
This because Cygwin won't let me manage it's tranparency server side.

I'm minded to try setting the KDE background to a wholly transparent image, and just let the Windows driver ignore the alpha channel. But I'm not sure how to do that, or if theres a better way.

Any thoughts?