I agree, contact customer service. I briefly used the Atmos AG pack, and had the same noise; one online reviewer says "it doesn't squeak, it crunches. It's not the metal frame making the noise, it's the stretch mesh." I didn't like the pack for other reasons (in a nutshell, too many features I didn't use resulting in too heavy a pack.) The AG suspension is comfortable, but noisy. I didn't keep mine long enough to see if it went away with time; I returned it to REI after one shakedown day-hike.

I am, however, very pleased with my Osprey Exos (both 48 and 58 sizes.) It's possible to tighten everything down and make it squeak, but you have to work at it. Adjusted normally, it's a quiet pack.

As far as Backpacker, I no longer read it - I suspect the reviews and recommendations are driven as much by ad revenue as actual performance tests. Backpacker used to be great, full of articles and thoughtful reviews. Now, the articles are merely collections of loosely related factoid boxes and photo captions, and the reviews are marketing-speak. Sad ending for a once-great voice about the pleasure that is backpacking.