Well, that was fast.
Just a day after removing Version 2.0.3 of the 5D Mark II firmware due to a bug, Canon has released firmware Version 2.0.4, which simply fixes the bug in Version 2.0.3.
We apologize sincerely for the inconvenience caused to our customers by suspending the availability of the Version 2.0.3 firmware.
We are now introducing the Version 2.0.4 firmware. This firmware corrects the malfunction that occurred in the previous Version 2.0.3 firmware, in which the manual recording level changed and made recording impossible.
Customers who have the Version 2.0.3 firmware on their cameras should update the firmware to Version 2.0.4.
Hopefully Canon got it right this time.
Thanks for sending in the tip Jonathan!