If you purchased your Qio before November 2011, you will need to update internal Qio ROMs to allow Windows to enable hot plug. This updater needs to be run from a Macintosh.
You need to download and install the Sony SxS UDF Driver, available here http://pro.sony.com/bbsc/ssr/cat-recmedia/resource.downloads.bbsccms-assets-mkt-recmedia-downloads-upgrades.shtml