canon says

[milto]

that the auto focus issue with the 1d mk3 can be corrected using the firm ware update, is it so

 

[Canon Bob]

Assuming it's one of the "known" issues....If the body serial number is later than 546561 then the fixes for mechanical problems (sub-mirror) should have been embodied prior to shipping. Firmware 1.3.0 should also have AF issues sorted.

Bob