Vista - Itunes makes my E Drive Disappear

When I install Itunes my cd/dvd drive disappears. It is not in my
computer and nothing happens when I put a cd or dvd in.
It still shows in device manager as ok.
If I system restore to before Itunes then the drive comes back.
But every time I install Itunes the drive goes away with the next re-boot
(or sooner).
I found a registry entry to make the drive come back and still
have Itunes, but this makes an erorr come out when I start Itunes that
says 'The registry settings used by the Itunes drivers for importing and
burning cds and dvds are missing.'
I tried changing my drive name from E to F, but the same thing happens.
Can anyone help?

--
Dan R

I also lose my E drive when I install iTunes. Then when I try to burn a CD I keep getting a message box poping up saying "The attempt to burn a disc failed. An unknown error occured (-50)"