I had a similar problem and was able to solve it by doing the following:
ran some MS tool that adjusts the "drive type" number in the registry
uninstalling all my DVD burning software, Drive emulation software, etc
uninstall the DVDRW drive from device manager
Hard power off (although still not fixed)
googled & ran "MS DVD FIX"
Some combination of the above fixes resolved, although the last step of running the "MS DVD FIX" was what finally cleared the problem.
(However, I think uninstalling the drivers and some of the other steps helped).
Hope this helps someone
(posted here because it's the top search on google for "dvdrw drive doesn't recognize blank discs")