Not a Canon in my case, but a HP6520. I had a Kodak for years but it got a bit unhappy when we printed a few hundred things on thick card, so I bought the HP some three months ago. Last week, the scanner started to sulk and every attempt to scan makes it display "Preparing to scan" but then it just sits there. Then four days ago it decided it needed an update. "Downloading update" ... "Download completed. Please wait". I left it turned on and waited for more than 24 hours, before I gave up and switched it off. Turn it back on and, yes, it notices it wants the update ...

Naturally, I don't have the receipt to take it back.
Oh, and by the way, the Kodak has recovered from its exhaustion and is now working happily again.