Did somebody realize that the pentamirror or the sensor is not in the right position? We just noticed when taking some photos on a tripod, that the pictures taken with a 450D are aslope (I'm not sure if this is the right English word for it).
So, what you can see in the viewfinder, will be different to the result photo, meaning, that for example if the picture in the viewfinder is positioned perfectly horizontally, the result will not be horizontal, but it will have a 3-4 degree of skew.
If we compose the picture using the live view, and then we check this through the viewfinder (using tripod), we can see, that the 2 scenes are not the same. There will be some discrepancy between them, meaning a few degree. I think this is quite annoying.
Can it be repaired in a service? Have you realized anything similar with your camera?