Hello, I´m about to buy a digital SLR and I was for Nikon D40x, when a friend of mine told me how wonderful the sensor cleaner of his Canon Xti was (he thinks I´m wrong with the D40x because I might miss the focus motor built in the camera). Anyway, I checked photo sites with personal reviews and found that many D40x owners have problems with the sensor getting dirty with dust easily. Is this truth? How often do yo have to clean it? Should I reconsider my choice regarding this feature in a Canon 400D?