Brian i don't understand why switching one of the servo around didn't help? If both servo horns are toward the back and both linkages are on bottom and the elev halfs move opposite. Then turning one of the servos around where the horn is on the front HAS to fix it.
I have had trouble with the reversing Y. It nearly cost me a plane when the trim changed in flight on the reversed half. I know many people use them with no trouble but I wont use one again. I bought a 9C right after that happened so I could drive each servo off it's own channel.

david