DVD roblem

Im am using a Lite On DVD/CD drive. i have a problem accessing my saved data in DVD/rw. Message says there was no disc. I was able to get some files before but when i tried to access it again, it seems that the drive cannot read the DVD anymore or cannot find it. I uninstall the Sonic DLA but still no luck.

Im sure the drive is working bec I can watch DVD movies on it and i have no problem using CDs. It’s just recently that when I insert a DVD with files, drive cant read it. I cant even scan it for possible virus.

What should I do? please advice. thanks!