Added 2nd DVD RW, Vista freezes on Start-up

Hi --

I have an machine with an internal IDE DVD-rewriteable drive which has been
working fine with Vista 32 Home Premium for most of 2007.

I purchased an internal SATA DVD-rewritable drive to give me a second DVD
drive. When installed, the SATA drive is properly recognized in BIOS.
Vista, however, loads up to the point that the desktop is displayed, but then
after a few seconds (during Vista's initial application loading/startup)
Vista freezes solid.

Suggestions? Happy to provide more info/clues

Mark