I've just received my brand new Dim 8300 and tried to replace the CDRW drive with my own Sony DRU500AX DVD burner that I've been using for a while.

It was running fine for a day, and then weird thing happened. As soon as the system is powered on (before even BIOS screen shows up) the drive starts ejecting and closing, and never stops. In fact, it does it even if I don't connect the IDE data cable.

The same drive works just fine in other computers, and the drive that used to be in this place works fine as well. I updated the drive firmware, it didn't help.
After some attempts to connect the drive differently I succeeded to boot up the machine without getting into open-close sequence (drive was on the floor, next to the machine). I thought that's the end of my troubles and placed the drive back in the bay. WHen I turned it on, I saw I was mistaken:)
Finally I made the machine boot up, drive sitting in its bay and not ejecting like crazy. I tried to put in a CD but I couldn't - as soon as I close the tray it ejects back! When I just hold the tray with my hand it gives up after a while and can read/write normally.

The computer seems to be fine with the drives it shipped with, so I cannot blame Dell for this. At the same time I can hardly blame Sony because it works in other computers.
Can anybody offer an insight on what to do?

Thanks in advance,
    Vladimir