I'm attempting to import the content from an existing wordpress.org blog to mbgross.wordpress.com, but it's telling me to "Please upload a valid WXR (WordPress eXtended RSS) export file."
What could be causing this problem? The original site is at http://defenderofkeys.com. I upgraded to WP 2.9.1 before attempting to export.
The blog I need help with is mbgross.wordpress.com.