M24, I believe you are correct in your assumption about the lubricant blobs. My new 30D had stuff that was obviously not dust on the sensor after only a few shots w/some burst shots. The stuff could not be blown or brushed off and it smeared as you stated on the first few swabbings. They were also in odd shapes that did not look like dust.
My 400D's sensor was also a mess the first time I checked it but I had quite a few shots on it by then. The stuff on it acted and looked the same way as the blobs on the 30D. The 400D doesn't seem to be as bad about getting dirty as time goes by. Hopefully my 30D and your 40D will be similar.



:p
