It's important that the .cue file is pointing at the right direction.
It's common that EAC encodes the single file as .wav
Example: The Beatles - Abbey Road.wav
or CDImage.wav
The .cue file has in most cases the same file name when you open it in a text editor or Notepad.
The most likely thing in your case is that the .cue file is looking for a .wav file, while your file is a .ape
Solutuion:
Open the .cue file in a text editor program.
Look for the part where the file name is.
remove the ".wav" part and write .ape instead.
Click save.
I'm not sure how to add the que into MC the best way.
I just drag 'n drop the que into the 'Playing Now' topic header.
Then chose 'Add to Playing Now' when I'm converting a single que file to mp3's.
Hopefully someone else has that answer?
/Higginz