DVD and CD Drives

Okay, I know this is a fairly common problem but...
I've got an internal CD RW and a usb DVD RW - which work fine most of the time.
Until I use my external 500Gb back-up drive or a virtual drive (Daemon tools).
Windows always pushes the DVD drive back to CD by changing its value in the registry.
Even if my burning apps show a DVD burner it won't work because stuffing Windows has changed the properties.
I know how to fix the values in the registry back to 1 and 2.
BUT is there any way to "lock" the DVD drive in as just that?
In other words, to stop windows showing it as a CD drive - ever?

*bump* anyone?

Whats the problem with it showing up?
If you know how to change the registry value to fix this you could write a batch file to do that and have it run on startup.