I own a 550D (T2i) and downloaded yesterday for the second time the ML firmware (the previous time was a while ago. I deleted it because my camera broke down giving ERR01. Canon said something inside was burnt. I thought it was because of ML and deleted it. (I deleted the firmware before sending it to canon)). So yesterday I downloaded it again and I was using my 550D today for a couple of hours, running on ML and the heat came back. The error isn't back but my camera was again really hot. Also, after switching SD-cards, mirror lock up was still active. Even without a SD card in the camera. When I inserted the card again and disabled MLU, everything was okay again.
Issue #1636 invalid