I debated and debated over where to put this....it's a Canon camera but a Sigma lens. I hope it's okay that I've landed it here.

The issue: Error 01-"Communications between the camera and lens is faulty. Clean the lens contacts."

I've tried doing a forum search on this, but I have yet to find someone with my exact problem. I own a Canon 50D that is approaching a year old. I have a Sigma 70-200 2.8 that the one year warranty goes out on Oct. 6th. (This is the same lens that you guys told me to have recalibrated some time back...which I did, and it helped my soft focus problem.)

I do not use this lens very often since I also have the Canon 135L now. That lens has pretty much grown to my camera. However, here lately I have pulled the Sigma out for some equine stuff, and was reminded of an issue that first came up back in the Spring...that I had simply brushed off. And that is... when doing several verticle shots in a row, the shutter noise will start getting "rattly" sounding. Hard to explain... but it's like it gets louder with more vibration in it. (Like there's a loose connection pretty much...which I think there is.) The first time it happened, I took the lens off and cleaned the contacts as it said to do. Didn't get the error anymore so, I didn't think anything else of it. Till now.

Last Friday, I did a shoot with my friend's children and their horses. I was doing lots of verticle shots...and it didn't take long before I heard that noise....then got the error. Cleaned the contacts and put the lens back on. Did some horizontal shots...fine. Switched to verticle..wasn't long before I started hearing it again...got the error again. Tried just switching the camera off then on...worked. Daggumit though, the moment I started back..got the message again. Switched to the 135L.

Went camping yesterday with the family and took the lens to see if I could *make it* malfunction again. Did a bunch of verticle shots...got the noisey racket...but never did get the error. Had I kept on shooting (had to tend to kids too though), I feel certain it would have eventually happened.

Got home today and I've looked up everything I can find on this. I've found lot of people with the err 01 problem with the Sigma lens on the Canon...but I have yet to find anyone that has the same exact issue. (Involving verticle shots only, plus that noise!..can't find anyone that mentions the noise!) I'm already planning to call Sigma tomorrow. What I'm curious about though is... in my online search, I found where this was actually a malfunction of the camera for a few people. So now I'm not even sure that it's the lens that has the problem. I'm starting there though...because I can actually move the lens side to side a little.

Also...I read where some thought it was a deal with the humidity..which in South MS, we have a LOT of humidity. But I only have issues with THIS lens...and besides, even after cleaning the contacts last week, it still did it. And besides, would humidity cause it to make that racket?
Anyone else have a similar problem??