Here is a good reference page for cable pull.

Bicycles/Maintenance and Repair/Gear-changing Dimensions - Wikibooks, open books for an open world

It was the 9 speed that they changed from 1.4 to 1.5 "shift ratio".

So, with 9 speed, your ok with:
New 9 Shifters + New 9 (or 10) rear derailleur & any Campy 9 speed Cassette
Old 9 Shifters + Old 9 rear derailleur & any Campy 9 speed cassette.
New 9 Shifters + Old 9 rear derailleur & SHIMANO 9 speed cassette.