The 40D gets a firmware update. You can DL it here:
1.Fixes a phenomenon in which Image Stabilization operation emits a sound when certain buttons are pressed, with the EF-S 55-250mm f/4-5.6 IS lens attached to the camera.
2.Fixes a phenomenon in which the Image Stabilization operation emits a sound from the lens when IS lenses are attached to the camera.
3.Fixes a phenomenon in which a part of the image looks unnatural when reviewed on the LCD.
4.Corrects errors in the Spanish and Norwegian menu screens.