Trassic,
While I don't know for certain if this will solve your problem you can try assigning the drives a forced entry letter, which will then save it in the registry
so all future uses of this device will be the same. I used this method for USB keys and had no problem.
Short Version > Run > DISKMGMT.MSC
Long Version > Open an explorer window, and right-click "My Computer", then select "Manage"
On the left-hand side, you'll find "Storage" and under that will be, among other things, "Disk Management" ... select that.
This will show your drives and partitions. In the upper part of the right-hand display, right-click the USB drive you have installed,
then select "Change Drive Letter and Paths..." then select "Change..." and a drive letter starting from 'E' since you want D to be your CDROM.
Now whenever you unplug/plug in that drive it will get the information from the registry rather than assigning one.
You can also do this by editing registry but this is a lot safer.
