DocumentWindow.Title no longer shown after OS Theme change

We use the MDI/Docking functionality of actipro and have recently upgraded to 2016.1.

This seems to have introduced a bug where DocumentWindow titles are no longer shown in tabs or on the document list menu after an OS Theme change - something that doesn't happen in the old version (2014.2).

This is actually more serious than it sounds as many of our users access the application through a remote desktop client and this can easily trigger a Theme Change event from the OS as follows:

• Start a remote session and run the application
• End the remote session, leavng the application running
• Start a new remote session - at this point the OS will issue a theme change event to running applications.

After a themchange, all DocumentWindow titles dissapear.  Even new documents do not show their titles.

If I look at the DocumentWindow objects in the debugger, the DocumentWindow.Title property is set to the correct string (we do this in code, not with a databinding) it just isn't displayed.  If we change it to something else it still isn't displayed.

So far I have only been able to get Titles working again (without restarting the application) by using the DockSiteLayoutSerializer to serialize the current layout to a string, close all the windows, then deserialize the layout back into the DockSite.  After doing this everything works again!  

So, I do have a REALLY UGLY hack to fix it by running the serialization/de-serialization on any ThemeManager.SystemThemeChanged event, although even that is not enough on its own - you have to wait a couple of seconds before doing it or it won't work!

Note that we do not really care about supporting different themes and don't have any code or xaml in our application related to themes.

I have tried to reproduce the problem with a simpler application, but no luck yet.  If I do I will post the code.

I'm keen to find a more robust fix to this asap, so any help would be very much appreciated.

thanks

Bill