I'm storing all localizable strings in a ResourceDictionary (in App.xaml) and assign those via the StaticResource markup extension to TextBlock.Text, Button.Content etc.
In Beta 2 and RC0, sometimes parsing the XAML in InitializeComponent() will fail with an AG_E_PARSER_BAD_PROPERTY_VALUE on the line and position where I set the attribute value to the StaticResource.
It only happens sometimes: When restarting the app, it parses and displays without any problems. The same interface code works for days or weeks, then it happens again.
Any ideas?