Pull ratio and rear mech shape changed in 2011. There is a compatibility chart in the Campag Tech Specs of that year (I imagine that is where you will find it, I have a pdf copy) which shows that 2011 10 speed rear mechs are not compatible with pre 2011 10 speed Ergo levers. I suggest that eBay or elsewhere might source a suitable mech.
Not quite accurate.
Pull ratio did not change.
As noted elsewhere in the thread, spring strengths in the RD did. In Centaur's case, the spring tension was reduced to that of the current Veloce, in Model Year (MY) 2006.
Confusion arises because in late 2009 / 2010 Campagnolo produced a specifc run on Veloce and Centaur RDs where the spring tension was "upped" to work with 10s UltraShift levers. This also allowed these RDs to work better with older ErgoPower levers of the non-"Escape" design. These mechs were discontinued in MY2011 when PowerShift was introduced and the "current" Veloce and Centaur RDs were introduced.
In fact, RDs designed to work with Escape 10s / PowerShift 10s (the requirements are the same) can work "OK" with older full ErgoPower designs and UltraShift designs but they are not optimal and the combinations are subject to a lot of provisos - cable runs need to be carefully executed and external. Metal ferrules (standard campag spec anyway), Campag inners and outers (in the spec anyway), care to cut the outers very square (in the spec anyway) no cable route through the 'bars ... in these circumstances, the shifting, if correctly set up, works fine but the longevity of the set up in the face of dirt, corrosion, wear and tear is less. The further one moves away from avery standardised set-up, though, the less well / predictably the system works.
I run Centaur UltraShifts with a Centaur RD for Escape, on my turbo-trainer / training bike... however, my chainrings are 53/39, my cassette is 12-25 and my frame is 73.5 seat angle, 407mm chainstays, 130mm rear end and Campag short road dropouts. So about as conventional as it comes. Other people with different arrangements, frame geometries might not find that the shifting works as well.
When Campag spec compatibilities (like Shimano and SRAM) they do so on the basis of averagely-good mechanical practice, a range of frame specs and an assumed rate of wear and tear on components, so their view of compatibility tends towards the conservative.