Ok... I've been sitting on this for a long time now, and thought I'd finally just throw it out there to see if anyone else has come across this.
The issue: Chain will derail as it comes into the lower rear pulley, as if the pulley is splayed outward and causes it to ride over the outside links and derail. It will do this from the get go if it is a problem, in fact, when initially installing the chain and before even attaching a derailleur cable it exhibits this. It is not and adjustment issue. The derailleur hanger is perfectly aligned. The hanger itself meets all Campagnolos specifications. As does the frame. And all parts are Campagnolo 2015 and thus compatible with each other.
Here's the pics showing what happens...
Just checking chain length per Campy specs... fine.
From the rear...
From the side, showing the pulley actually derailing off the outside of the chain...
This was a new 2015 setup on a previously perfectly functioning pre-2015 Super Record setup. No issues with the previous setup. No matter what the derailing would occur. This is in a small/small combo so it for sure highlights the issue but regardless the chain should run smoothly in that combo as well. Even tried adjusting the limit screw so far in that it would almost shift to the second cog but the issue remained.
Took the derailleur and installed on a different frame that was running Campy SR perfectly. Same thing. Would derail. But it was really hard to see where the SR cage was (if in fact it even was) bent. Did a lot of checking with three different derailleurs... 1) a pre 2015 SR derailleur; 2) a 2015 Chorus derailleur; and 3) a 2015 SR derailleur. The two derailleurs that worked fine, when placed pulleys cage down on a perfectly flat steel surface would not wobble. The problematic derailleur in the same situation would have a slight wobble so that's when I first figured the cage assembly must be slightly bent.
A second derailleur was sent to me from the same supplier that did exactly the same thing, at which time I was going crazy thinking I must be doing something wrong with the 2015 stuff. I wasn't.
Finally, I decided to swap cages with the pre 2015 SR derailleur that was working fine. And the problem was solved. So rather than have a 3rd derailleur sent to me, I opted for a Chorus cage, confident that the problem was isolated to the cage. And it worked fine after that.
I'm posting this here, because I asked about this at a shop I go to sometimes if they ever encountered it and they said "once", but they could never figure out how to fix it. The customer was eventually given another derailleur and when I asked if that fixed the problem they said they didn't know as he never came back. Probably very frustrated at that point I would bet. I did internet searches for this issue but didn't come up with anything. Yet I personally have seen two derailleurs like this, and know of a third that I just mentioned. And they all came from the same supplier so I'm thinking this may have affected a very small batch of derailleurs. But I just want to post it here to see if anyone else has experienced the same thing. Hope not, because it was frustrating to resolve.
I fear however, that there may be some rich coffee shop mamils out there bragging about their Super Record stuff and how it's the bees knees then after their coffee they go riding off to the sound of a semi derailing chain. lol. Not good. Now, sitting around talking about your bikes is just fine, but it better be silent when you ride off. We must do what we can.