Export only creating blank .xml files

I’m migrating our WP blog from one server to another and have tried several times to export our existing data using the export function in the admin; however, regardless of whether or not I choose all authors or just a single author.

We need to migrate the blog ASAP (I’d love some help, pro or otherwise) and I need to know if there is a patch or trick to exporting or if we’re going to have to use the more complicated MySQL route.