I got an error downloading the .xbap as follows (after fishing it out of the log): "ERROR SUMMARY Below is a summary of the errors, details of these errors are listed later in the log. * An exception occurred while downloading the application. Following failure messages were detected: + File, Swimming.wmv, has a different computed hash than specified in manifest."
That's great news about the font licensing if it goes ahead: I've been suffering serious font envy ever since I started reading your blog.
As for the difference, I'm woefully ignorant of typography, but in the second example it looks as if the numerals are rendered as lower-case characters with acenders and descenders, and in the first example they're um, not.