Sony DRU-720A with PWS 450

I replaced the OEM 4X DVD Drive with a Sony DRU-720 16X Drive.  Have XP Pro SP2 and all updates.  As up-to-date as possible on BIOS after checking Dell site. 

 

Using removeable HD for main boot drive.  Two boot drives to swap in/out  -  one is original HD from Dell,  second is a video editing only HD created from Recovery CD. 

 

Both were working fine prior to changing DVD drive.  After changing DVD drive the original HD will not boot, however, the video HD will boot.  No error message on screen just blank after Dell logo and dos message (standard loading info for Promise drivers, etc). 

 

As far as I can tell the HDs should be the same for boot purposes, only limited additional software on video editing HD, no e-mail, games, Office, or anything else.  Swap back to original DVD drive and everything is fine - all HDs boot. 

 

Checked data in Setup and both old or new DVD drive is being recognized by Bios.  Any suggestions or ideas would be greatly appreciated.  Swapping DVD drives is a lot more trouble than swaping a removeable HD so I will only do that when I need to burn a bunch of DVDs.  Thanks in advance. 

 

Al