What happens when you insert a tested known working dvd and try to access it? this may be representing its current media state. I have also seen the microsoft cd writer wizard cause this to happen when files are bound waiting to be written to cd in windows xp, however we don't know what OS version and what dvd drive you have, can you post that information here?
Update: likely theres either an issue with your burning softwre or your dvd drive "device" within windows. uninstall the cd-rw drive in device manager, and reboot. If that doesn't help attempt uninstalling and reinstalling your burning software. likely one of these will fix it
windows 7 have cleaned disk and reinput windows 7
dvd rw and cd r worked ok for two days
then dvd rw reverted bancik to cd r
dvd/cd rom drivers
tc cd rom fswee ata device hl dt st dvdram gh 22nsto cd rom device
DVD drive are also CD drives and Windows will report them in My computer based on the Disk that is\was last inside the drive (IIRC) so try placing a DVD in the drive and see if it gets read properly -If it does then no need to worry.