DVD Drive Problems

Sometime betwen now and mid June 2004 something has impacted both my disc drives. I have a Dell Dimension 8300 with Win XP Pro which came installed with an NEC DVD+RW ND-1100A and a LITEON DVD-ROM LTD 163. Had this system since July 2003 and had no problems copying and reading files. I do not use either drive very often, Only for an occasional saving of important files. I have NOT downloaded SP2 yet. I was about to do it and they suggested I save important files before doing the download which is when I noticed I had a problem with my disc drives. My device manager tells me all is well. Both drives working properly. When I attempt to update the drivers the wizard tells me it can't find a better match than I already have. The DVD-ROM drive does not appear to be recognized at all. After insering a CD-ROM disk, even one that I know has instuctions or course materials on it, it does not launch the contents automatically like it used to. Then clicking on the drive produces a message telling me to insert a disk in the drive when there is already one there. The DVD+RW does not launch the contents of the CD-ROM either but it does not produce the insert disk message. It simply shows the drives blank screen, no contents. It appears that I can write files to blank CD-R discs. I can see the available space of the disc decrease. I just can't go back and read he contents. Please help. What do I need to do to figure this out? What could cause this problem out of the blue? For a DVD-ROM drive to allof a sudden not recognize a purchased CD-ROM is pretty scary. The only recent change made to my system was to replace my cable modem for Comcast cable. I do not think that should have had any impact on Windows or my disc drives.Can I be assured that if I uninstall both drives via device manager, both drives will definitely be re-installed automatically by restarting? Don't want to dig a deeper hole. Any help would be appreciated. Thanks. -- David