Just for the record, I took all my test shots with the camera mounted on a tripod, in bright light, with fast shutter speeds (500-1000). In addition, I noted the same focus problems at f5.6, f8, and f11 (although at the smaller apertures, the focus issues were less noticeable due to the greater depth of field). All shots were taken at ISO 400 (since this is my most used speed), and in JPEG Fine. The images were compared in both Canon Fileviewer and Photoshop.
Chesty,
One interesting observation: In reviewing the other posts on this site regarding 10D focus issues, you noted in your post to PHOTOKAT on May 20 (day #4 with your new camera), that your focus appeared to be "spot on" and you were very happy. I looked back chronologically through my images and it appears that some of my earlier images were in better focus than more recent images. I dont know if this was a result of our initial awe and amazement with the new cameras, much more stringent and formal testing more recently, or if something (physically or program/setting-wise) changes with time/use. The reason I bring this up is that other posts have suggested that resetting the camera settings seems to improve focusing -- at least temporarily. Resetting did not seem to correct the focusing issues for me, though.
Again, I will look forward to hearing your results with great interest.
Good luck, Mike D.