Apres relecture, il semble bien que tous ces n° sont affectés par ce défaut.

"This phenomenon affects all EF 70-300 f/4-5.6 IS USM lenses with a "0" or "1" in the third digit of the (8 digit) serial number. Products that have a third digit of "2" or higher in their serial number are not affected."

A moi le retour au SAV