CD Unit does not detect the media

Hello,

My CD in Windows XP Professional only detects the media I insert when I
delete the device from the device manager and reboot. On the next boot, the
CD does not react at all to the media. When inserting a disc in the unit and
clicking on the unit in the explorer I get the message "Please insert CD in
the unit D:".

I have changed the HW for a different CD-ROM, and the behaviour persists.
It did not happen before.

Is this due to an automatic patch? Does anyone have the same problem or a
solution?

Thanks for your help

Pablo