Great cameras, but they do occasionally mis-focus. One thing that takes a while to understand is that you want to lock the AF within one of the little ] bars, not in the middle of them [ ]. You will usually know when it is going to mis-focus because the lens will lock when you half depress the shutter button, then when you fully depress the shutter button the lens will travel in, then back out again. These cameras are notorious for having focus difficulties w/ the 90 lens, but you should be ok w/ the wide angle and 45 lenses. The focus problems are on a camera by camera basis. I just use the manual focus on the 90 lens when in doubt. Once you get used to it it is surprisingly easy to manually focus the camera. It is a real pleasure to lock the AE on this camera too. I usually do that to lock in my metering, then compose and focus and shoot.
Other issues are: make sure the lens contacts and the lens mount are perfectly clean. They have a habit of getting a blue oxide on them. Just wipe them off w/ a little alcohol on a rag. The lens needs to make perfect contact w/ the body to communicate aperture and focus info. And lastly, sometimes the shutter buttons will get a film on the contacts and cause the camera to behave erratically. It is a good idea to every now and then take the camera out and depresss the shutter button hard and fast about 10 or 20 times as this will clean the contacts. The Hexar RF has the same problem.
