V-Vocal weirdness in X3

Issue: a couple of clips in a "chorus" section were treated with V-Vocal. When I copied the chorus section which included clips across six tracks and pasted them to another "chorus" section of the song, the clips with V-Vocal wouldn't sound.
I tried to apply the effect to the clips but the end result was a flat line. (no sound).
Then I removed V-Vocal from the clips which made them sound again although with pitch problems, then added the V-Vocal layer back to the clips, corrected the pitch and it worked fine.
This happened every time I copy/pasted.
That never happened in X2.
Anybody know what might be going on, or is this a bug?