DVD drive found only after resuming from Sleep

Hi All,

Looking for some help here from a very unusual problem.

I have a Plextor 716-A DVD drive in my machine that's running Windows 7 32-bit, ASUS P5Q deluxe MB and 2 x SATA HDD's.
The DVD drive is not found by Windows on start-up, it does not appear in My Computer or in Computer Management - basically Windows knowns nothing about it.

The DVD drive is found in the BIOS and I can see it's being loaded during boot-up. I can use the drive as a bootable drive.

The drive is only discovered by Windows when I enter and then resume from sleep mode or hibernation and works fine.

I've gone through every article I could find on the Web from Mr Fix it to the Upper/Lower Filters regedit.

Any ideas?

Jeff