Disable all emulations, especially any kind of Hide CD-R media function (e.g. Alcohol, Daemon Tools Pro, CloneCD, etc.).
Note that NO emulation is required to use mounted images!
Emulations are for written media only [i.e. CD-R(W), DVD+-R(W)]! Thus emulations should be enabled when really required only.
So keep the emulations disabled unless you use some disc that needs emulation.