It seems that Canon has made an announcement that the new 2.0.3 has a bug. We can assume that a new version will be coming shortly to address this issue.
This release added new video features to the camera. The problem is that the new audio doesn't work if a manual record volume is set in one of the 3 custom modes (C1/C2/C3). You can read more about this issue at this LINK.
There's a reason I don't install new firmware updates the day they're released. It's also a good idea to download and archive old firmware updates so you can roll back should you find a problem with a new firmware release. You must do this before a new release is posted as Canon removes old firmware releases from their website upon issuing an update and they won't give it to you no matter how much you beg and plead.