Double cd's

I have several cd's that exist of a normal edition and a special edition.

When I want to add the special edition after the normal edition it says that the cd is already in the database.

But this is not true, cause the special edition has 2 cd's and the normal edition just 1.

The first cd of the special edition is indeed the same as the normal edition.

How can I add my special edition with 2 cd's.

... and sometimes that special edition has a DVD for the second media. I would like to be able to have the CD and DVD recognized as one set of two media ...

You can duplicate Cd (Tools > Duplicate) then edit