Anyone have that problem? I have a Sigma 70-210 f/2.8 APO lens I bought a zillion years ago. I have shot plenty of pics with that lens since I got the 40D and it's worked fine...until last night. I mounted the lens as normal and got a ERROR 01 - this means the lens is not communicating with the camera. The AF worked fine, but if I tried to do aperture preview or actually take a shot, the error would hit me. First thing I did was clean the contacts on the lens. I used alchohol and a Q-tip and tested, then a polishing cloth and tested, then a pencil eraser and tested - no help. So I grabbed my old Sigma 28-200 f/3.8-5.6 "vacation lens" (translation: cheap, so it doesn't bother me so much if I drop it over the side on a cruise ship...). It worked before as well - now it gives the same error. Did the same cleaning thing, no help. BTW - My Canon lenses work perfectly. Just these two Sigmas have problems. Just to be thorough - I attached them to my old EOS A2 and EOS Elan II. Both old Sigma lenses still function prefectly - including aperture - on those cameras. Canon's tech support gave exactly the answer I expected: "not our problem, talk to Sigma." Sigma's web site has no compatibility chart for lenses that old. What burns me is this: for three months, these lenses have worked perfectly. Now, the same day, same time, they fail. Seems like my 40D doesn't "like" Sigma lenses all the sudden. I smell a massive conspiracy. Well, okay, not a conspiracy, but I'm chafed because I can't afford new glass. Anyone?