In reference to this thread http://www.bikeforums.net/classic-vi...l#post17644359 regarding a slipping Campy down tube shifter I finally went to the hardware store to buy a stainless steel washer. I installed it on the shifter D-ring screw and it stopped the bottoming out of the screw in the braze-on boss and now all is well. It took a long time to get to this point because everybody was telling me that the problem was either derailleur alignment or high friction in the cable run. I wasted a lot of time pursuing that but eventually it turned out to be too little friction (in the shifter) rather than too much (in the cable). The good side of the "high friction" detours is that now I have substantially reduced the friction in the cable run so the shifts are smoother and crisper than before. A bonus on top of fixing the slipping shifter. Thanks for all the folks who helped me through this annoying diagnostic adventure.