Did your burner come with a driver CD? If it did, delete the previous installation and reinstall it, you should also see if there are any newer drivers for it.
If your burner is of the plug and play type, unplug the IDE and power cords and turn it on, then back off, reconnect the cords and see if the device shows up as "found new hardware".
An after thought here, if you have a disk in your tray that you need, you can manually open the case. Just below the tray there is a small hole, if you take something like a paper clip and insert it into that hole and apply gentle pressure it will open.