Will not see dvd disc in dvd device

No issues with earlier builds, but on one portable and one server I am now getting issues with the RTM bits where the dvd disc stops being read by the dvd drive.

What is weird, is I start the load process from the dvd drive no problem.
But, after it goes a while, I get an error on both of these different machines that there is no valid cd/dvd driver and will go no further in the install process. (Works fine on a different portable I have). On one portable, I hook up a USB drive and load the OS from it.
When loaded, I look at device manager, and it says the dvd drive is installed,
and all the drivers look fine. But, if I put a CD or DVD into the drive, nothing.
I know everything is good, so what changed in the RTM bits and how do I fix?

Dave

Update driver for DVD -check in Windows Update or manufacturer website

Looked into all that. MS just load a std driver.

As I said, loading the RC's had no issues.

And, the RTM builds starts, but then gives the error cant find a driver.
So, something is different with the RTM process compared to the RC process.

Once I try to get the paging file fixed, back to looking at it.

Dave