Hi
Have you tried using some other software like imgburn to see if you can write to the drive?
The fact that it's intermittent make is sound more like a hardware issue, usually with drivers either it works or it doesn't.
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Try installing ImgBurn (it's free) and will do pretty much anything you would need, and see if it works, if you haven't already tried software other than Windows.
I like using it better then Windows anyway, just have a link on your taskbar, but if it doesn't work maybe that would indicate something, or give some kind of message about why it won't work, i.e. drivers etc.
You could also uninstall your DVD drive in Device Manager and reboot, Windows should install the correct drivers for it...