Sorry I omitted the hotfix link:
When you connect a USB multifunction printer device to a Windows Vista
-based computer, a second instance of the printer object is created,
and the first instance no longer works
http://support.microsoft.com/kb/934633/ contains the following symptom
When you open the Printers item in Control Panel in this scenario, you
experience the following symptoms:
• In the list of installed printers, there is a second instance of the
printer object for this device.
• The original instance of the printer object is set as the default
printer. However, the original instance of the printer object does not
communicate with the multifunction printer device. Therefore, this
instance of the printer object does not work as expected.
But I hope the answer is in the driver ....