Canon lenses purchased overseas no longer have an international warranty in Australia.
Looks like they are trying to cut off the grey market on lenses.
September 1, 2011: Canon has announced the introduction of region-limited warranties for Canon interchangeable lenses, Speedlites and IS binoculars for Australia and New Zealand.
Effective today, this change – from international to local warranty – follows on from an across-the-board local price reductions for Canon photographic products in August and the launch on Monday of a Canon retailing website. Canon says these initiatives are designed to 'attract consumer attention locally' in the new globalised marketplace for photographic products.
Purchasers from overseas sources will be either directed back to their point of purchase to pursue warranty service at the country of origin, or offered service by Canon for a repair fee, as is the case with out-of-warranty repairs.