Sorry for the lack of information. System 1 that I am mainly using
Unknown brand slot1 motherboard
Pentium 3 600mhz - 320mb ram
IDE DVD-RW on primary IDE
16GB CF-> IDE on secondary IDE
Windows 98SE with Autopatcher 2007 and 2008 update installed
VIA chipset drivers installed
On that system I did have an 80GB Seagate IDE drive, Same setup without the autopatcher updates, and I did have MSCDEX set up because I was booting into DOS with a menu to boot windows later if I wasn't going to play games.
I started fresh because that HDD got the tick of death. I don't have a dedicated DOS setup now, I had installed Win98 right after a fresh format and sys c:. I didn't copy any other files from the startup disk.
The other machine is bone stock original hardware / factory installed OS - Packard Bell Aloh@ 5860i
Windows ME
256mb RAM
700mhz Celeron Socket 370
40GB IDE HDD
DVD ROM
I switched out the 40GB for another CF adapter, installed 98SE, Installed Intel chipset drivers first (otherwise couldn't install onboard intel graphics)
exhibited the same thing, push the button and the cd rom will eject but windows didn't see the change. You can 'eject' from windows with nothing in the drive and it will free it up.
I put the factory Windows ME HDD back in that PC and it doesn't do it in ME.
The main pentium3 machine doesn't have any burning software installed yet, or daemontools or anything of the sort. It's possible something that was installed in the updates is causing this too I suppose, but I wouldn't even know where to start besides do a fresh install and don't update anything and see if it still does it.
I did try another DVD rom in there and it exhibits the same behavior. I don't have any plain jane CD rom drives to try, it might even be a DVD bug.
Sorry my post is all over the place.