i was told by them... even any cannon user lost warranty card or the invoce they also can help us to trace back on the system when the cam is place on store for sale and base the warranty around the period.
what they want is to provide GOOD sevice......
got my cannon cam 2nd-hand from one of the member in CS, but i lost the invoice accidently
in the process...(warranty card unfilled too)..
but i registed the warranty online with the seial nos. on my cam...(grey set cant registed,so this is also a good way to check wheather ur set or canon...