So after reading tons of awesome reviews about the prime EF 28mm f/1.8 lens, I sprung for it and ordered it from Amazon.com. It quickly arrived today but, I am sad to announce that I will be returning it just as quickly as I got it. The problems I'm having with it have to do with the focusing. The USM technology claims to be near silent... while I didn't expect it to be dead silent, I expected it to be quieter than my other non USM lenses. As it turns out, I was mistaken. The auto-focus makes a fairly loud squealing sound or squeaking sound. It sounds as if the parts need to be lubricated or they're rubbing against each other. Not only is the sound different than what I expected but, the focusing is very slow and inaccurate compared to my cheap plastic lenses. Also, auto-focus seems to lock up after only a few minutes of use and I had to keep pressing the shutter release button to get it to unstick. All of these things lead me to believe I got a defective product. If anyone owns any USM lenses, can you tell me if anything like this is normal... it certainly is annoying and doesn't seem right.