I have a Storyboard that animates an Ellipse on a navigation:Page control. As long as I keep the Storyboard local inside the UserControl.Resources the animation runs with no problem.
I moved the Storyboard into a Resource Dictionary to make it available to multiple pages. I can access the Storyboard as expected, but the application throws an exception when the Storyboard attempts to locate the element to animate. I get a 'Cannot resolve TargetName' error.
My guess is that since this is a Silverlight navigation application the Storyboard needs to know about the application hierarchy to get to the page to find the final target - I just don't know how to make that happen :)