Tout est dans le titre, Canon a d'ailleurs retiré le firmware du téléchargement. En effet il semble qu'il y ait un problème avec le réglage manuel du son...

Recently we have discovered a malfunction that occurs with Firmware Version 2.0.3, in which the manual recording levels for C1/C2/C3 are changed and the camera becomes unable to record audio if the power is turned off (or if Auto power off takes effect) after registering "Sound Recording: Manual" in the camera user settings.
We apologize very sincerely for the inconvenience, but we are going to stop making this firmware available for download. For customers who have already updated to the new firmware, when using the camera with the mode dial set to C1/C2/C3, please either set the sound recording settings to Auto.
We are currently preparing firmware that will correct this malfunction. As soon as those preparations have been completed, we will let you know on this Web site. In the meantime, we apologize for the inconvenience this represents, but please wait until the fixed firmware is ready.