Problems phase AF

First of all: I do not count myself to the kind of person who ordered something, just to make it short at home to be able to try it and then to write the weak points in a review and the product is then re-sending back. I have the EOS 600D therefore bought with 18-135 kit also the "double-M" directly, because I could try there too (as far as possible, of course, that you have in the store).
For me, in addition to the quality photo and video mode is important. One hears again and again that one should better define a separate camcorder for HD video. I disagree, because you can actually very, very good create video with a DSLR and the right accessories. This leads me to the first point of criticism, which however primarily concerns the lens. But when putting the focus (manual) from the foreground to the background (which is at the movies again and again an important effect), "snaps" the picture eventually jerk off to the side. In the video, it looks like this, as if you had pushed against the camera. It may be that this effect does not really stand many, but those who value quality, the dislike this certainly. The second weak point of the lens: the focus areas are shifting within the focal length, that is, if one focuses on 135mm and zooms eg on 35mm, it is blurred. I've googled for this problem and am really find anything: the effects have a user typing posted on Youtube (just enter "Lens and focus problem Canon 600D" Apparently it's better with other lenses..

But the main problem of the camera: I noticed that repeatedly photos were totally blurred and this especially at 18mm focal length. I am of course aware that the zoom lenses do not get the best performance in this area at maximum aperture. But at several photos one can no longer speak of sharpness at all. After many test photos with a variety of settings (I have determined for 2 days tested), I then found out that only the photos that have been directly through the viewfinder (but with activated AF) made are concerned. Live View shooting (when the monitor screen) were actually quite useful. There another AF method is the Live View used (to contrast AF calls) than with viewfinder shooting (phase AF). The problem seems well to be independent of the above-mentioned objective. For I have initially suspected the problem on the lens, but with the Tamron 70-300 it was the same problem (also tried with different focal length settings). All comparison images were taken on tripod with remote release to exactly the same shutter speed and aperture Paramtern to obtain reproducible results. It really is 100% understandable that is focused blurred with viewfinder shooting.
Today I was at the said business and the seller of this problem could adjust even under adverse lighting conditions in the store. We have replaced the body, in the hope that there is a single problem. Before the business, I then shot (Live View and search receptacle) 2 Test Photos - same problem.
Is there perhaps a series problem with the cameras, which were delivered after the tsunami? I would be interested if other users also have this problem or previous models had already.
It's a shame I had already fallen in love with the camera, because actually it's really great. However, one so buys a reflex because of the bright viewfinder image, as one would like to do not only live view shooting and look at the monitor (especially as the focus speed is very slow), since this is going on the battery performance. For this reason I have returned them serious courage again and can forgive a maximum 3 stars. Were above problems do not exist, it would be of me 5 stars.