I am working on a large WPF project and during debug my output window is filled with these annoying warnings:
System.Windows.Data Information: 10 : Ca
This worked for me. Put this in your Application.xaml file.
from...
http://social.msdn.microsoft.com/Forums/en-US/wpf/thread/42cd1554-de7a-473b-b977-ddbd6298b3d0