Why is my WPF Frame not rendering anything? Known bug?

I have a WPF Frame with a web-based HTML source and though the contents are there, they aren't showing up. I know that the content is there because if I right click in just the right spot I ca开发者_JAVA技巧n save images. Also, if I do print preview it shows just fine. The stuff is there, but it isn't showing up. Is there a known bug?

I used code from here to create a placeholder control with a window that floats right above it, so I could put the frame in the window. Its a hack but it works... sigh.