Click doesn't get through invisible window on remote machine

[slava]

Using UltraVnc viewer (Win7 -> XP Home sp3). Both stations have the last version [1.0.8.2] of UltraVNC.
I connect to a remote machine. The remote machine had a center region that did not respond to mouse clicks, apparently there was an invisible window that was capturing mouse clicks.
That invisible window was in the center of the screen and every time I clicked in that region the top (focused) window was getting into background. Then i captured the handle and the app owner of that window.

Here is a screen with details of that window handle


The application is the dimdim plugin for screen sharing

[B]

Interesting detective work; thanks for sharing.

I tried DimDim once or twice but don't recall having to install local software. I thought it was Flash or perhaps Java.

[slava]

Interesting detective work; thanks for sharing.

I tried DimDim once or twice but don't recall having to install local software. I thought it was Flash or perhaps Java.

Dimdim now allows you to share your desktop screen by installing an additional software that captures your screen and sends that to server or eventually to every connected member of the created room -- I don't know technical details.
Dimdim plugin has a window, and I suppose it has a special style and UltraVNC: sees as an active visible window -> sends mouse events -> that invisible window gets focused, this way the top focused, centerd window instead of being focused looses the focus.
That plugin window is invisible or is transparent and i think somehow it redirects mouse events through itself when using desktop ( not in remote).