My HP DVD 400i will read movies and audio cd's, will also burn audio cd's, but will not recognize a blank DVD. Doesn't even know that's it's in the drive. I've uninstalled and reinstalled all related software, and even pulled the drive itself out to have it redetected. Nothing works. I did install the latest firmware update from HP, but that was also to try and fix the issue, it wasn't working prior to that either. HELP!!!