Are you using a new version of the desktop manager? When I downgraded my 8830 it a first did not see the older version. But then I clicked on applications loader icon, then start under update appications. It then showed the older OS version and would downgrade. One more thing, you could first go into control panel, add remove programs and delete any other versions of the device OS you see there, other than the one you want to use. Make sure vendor.vml is deleted, then re-start the desktop software and try it again.