Specifically, with 3rd party rings. I've been running q rings on Hollowgrams with SR 11 derailleurs and shifters, Record levers. It seems to happen when slightly crosschaining and the chain loses tension a bit and then falls to the small ring. Only happens when the front derailleur is trimmed. All limits are fine and I've taken it to two shops as well as a friend that is a Campy diehard. Their comments were all that its the q rings and that in particular 3rd party rings often throw the chain in front. I've never heard this so I wanted to know if anyone would corroborate it? I would like to keep my rings and I'm not sure I want to switch to Campy rings at this point in time.
One thing that caught my eye was the several replies that indirectly suggested to use / adjust your front derailleur so it becomes a means via rubbing the chain
to keep a chain from falling from the large chainring to the smaller chainring during normal pedaling. One poster also suggested a chain watcher - why for this situation???? - yes it might be nice for when shifting to the small and the chain keeps on going..... but the OP's situation is chain falling off the large chainring. (BTW - I don't use a chain watcher myself as have NEVER dropped a chain shifting down on Campy 10 or 11 spd).
The OP also mentioned the chain does it abnormal thing during moments of less tension......less pedaling tension comes to mind.....so in that case it's also nothing to do with the rear der tension because it's applying pressure to/at the bottom of the chainrings - the fall off is happening 180 degrees from there. I'd point the blame squarely at the abnormal chainrings/crank.
In my own situation, I am sometimes in a bail out situation where I find myself in the big big with a full campy drivetrain - no problems....the chain stays put on the gears intended.
for full Campy setups, and likewise for full Shimano and full SRAM.