Something else must cause that message on your rig; i'm sure it's not DT or YASU.
What kind of image do you use now ?
P.S. You never need to check emulation options when mounting images. They're only needed for burned media.
-EDIT-
Just to be sure:
Do you get "Please insert the original disc instead of a backup (1000)" OR as you wrote something with emulation detected ?
If it's the first you can try this mds file with poseden's mdf:
http://www.sendspace.com/file/yt9rlz