Crossfader for decks C & D wont function correctly!

So yesterday I was working on a customization of the VCI-400 EGE 1.1.2v mapping. When I noticed at some point that the crossfader wasn't working when it came to mixing in decks C and D. If you move the fader to either side you hear both decks. But say your mixing with decks A & D or decks B & C the crossfader works as it should, as well as when you mix with the standard decks A & B. I'm not sure why it's glitching out like this, I've even tried the following things to trouble shoot the issue but still having the same problem.

- Restart Traktor pro 2.1.1 and VCI-400EGE
- Restart Macbook
- Delete the mapping I was working on, restart, and reload DJTT 1.1.2 mapping.
- tried adjusting CF curve.
- Delete Traktor and associated files, restart and reinstall TPro 2.1.1
- Deleted DJTT 1.1.2 mapping and loaded Groovemixer's mapping
- Compared between all 3 mappings ( DJTT, my edit, Groovemixer's) there is only one mapping for the crossfader in each one.
- Canned air in Crossfader track.

After trying all these things I can't figure it out and it's probably something stupid. Any and all help would be greatly appreciated.

Thanks,
- mike