TO me sound like a problem with the g-springs and i would change the carrrier too.

One detail, what campagnolo are we talking about here? Campagnolo 10 has 2 mechanisms and if you have scape the gsprings and carrier solution wont work because escape doesnt have those parts at all.

Are you sure the cables are ok? some clueless campagnolo users just think the cables do not need adjustments and after a couple of years they complains saying that campy sucks when is clearly a user problem.

Good luck.