Modal RibbonWindow doesn't appear on second monitor

Feb 10, 2015 at 7:24 AM
Edited Feb 10, 2015 at 7:59 AM
My application launches a modal RibbonWindow, which usually works fine, but a couple of PCs here have a strange problem. If I move my application's main window onto the second monitor then open the modal RibbonWindow, it doesn't appear. Instead I just get a button on the task bar, which I have to click to restore the modal window.

All our PCs are Win7 with two monitors. Any idea why this is happening, and stranger still why only on a couple of PCs? I can confirm that the RibbonWindow owner is being set to the application main window prior to calling ShowModal(). The RibbonWindow.WindowState is set to Maximized, if that makes a difference.
Feb 10, 2015 at 9:47 AM
As we moved to GitHub, please ask questions or propose bugs there
Marked as answer by batzen on 5/18/2015 at 11:32 AM