I have encountered the most bizzare keyboard issue since I started working with WPF.
In a certain mode of my app, I find that the "c" character cannot be typed inside any of the text input fields. The "C" keyboard key itself is fine. It works in other applications. Ctrl+C works even in my application. If you copy a text with "c" to clipboard, you can paste it to my application just fine. If you switch to Russian layout, Russian character corresponding to the "c" key can be typed in my application without a problem.
The app is a hosting application that loads plugins. It has an Infragistics ribbon window, a couple of legacy winforms controls and a WPF tab control that loads children in another app domain using MAF's INativeHandleContract mechanism. The specific mode when "c" does not work is a "plugin debug" mode where I load a single plugin directly on startup. In normal mode, where I load plugins on demand after startup, "c" works correctly. The behavior is the same with or without the debugger.
I am not aware of any keyboard processing routines in my application that would suppress the "c" character. So, the $1M question is: how do I find out who is eating my c-heese?
TIA