I have a Memorex DVD-MAXX1240 and a Lite-On LTR-16102B installed. If I boot up the PC and there is no cd in any of these drives then I cannot use them. They show up in "My Computer" and according to system properties there is no problems with the devices but if I insert a disk it refuses to read or read/write in the case of the Lite-On. I then have to uninstall both drives and reboot the pc for them to work. Any suggestions................?