I just received my 50D, charged the battery as per the manual and it's not working. The charger says it is fully charged, but once you turn the camera on, and then turn it off it won't come back on again. If you remove the battery and put it back in the camera usually comes back on (not always). I called the company I purchased it from here in Canada (Vistek) and they say it sounds like bad battery contacts, and that I should return it to them to have a look at. So it looks like it is going back, so now I wait again for a 50D. On the plus side I also purchased a 17-40L, and it is tack sharp. A very very nice lens.