Windows Burn Dialog box not working in Vista.

Hi, I upgraded from XP to Vista Home Premium.

When I first installed Vista a week or so ago I could go into windows
directory. Select a file. Select Burn. Choose from drop down menu. Now I
click on burn in windows directory and the DVD/RW light sometimes flickers.
No dialog box.

Before I could Insert a DVD then a menu would pop up basically asking me
what I would now like to do. That does not happen now, no menu.

I can burn videos, photos etc from both media player and the media center.
So I know its not the drive thats a problem.

The dialog boxes are still there, and working, in Media Center & Media
Player.

Things I have tried include Uninstalling the driver & reinstalling.
Uninstalling the player/recorder & reinstalling.

Tried every setting in the Auto play services box including the 'Ask me what
to do box'

Doing a system restore as far back as I could go (lot of restore positions
were lost because I used windows updates and the oldest restores 'fell off
the list' so to speak.)

Tried a system startup repair using the vista disc, but it could find no
problems. Have tried lots of other things, but obviously none worked.

I really hope that someone can help, its a most annoying problem.

I am sure its just a file in reg that needs changing or a dll missing?

Really hope someone out there is clever enough to help. Thanks!