If you would pay for a driver, you may install a turboprint-driver. They take about 25$ for the driver.

My canon-3000-bjc isn't supported too. Priniting from my laptop I got a big banner on my printing 'Buy a license key'.
On the desktop-system It worked without such a banner.
Surprising.
Now I copied the settings from the desktop to the laptop and no banner too.
Perhaps there is only a random-banner?
Or it depended on the format - in the first time I printed directly from openOffice.
Later - without the banner - I exported my letter to pdf, and printed it with:

knoLi-2.6.5# > lpr letter.pdf

Perhaps it depended only on the file-format.
Since I print about 2 pages per month, I'm not willing to pay 25 bucks. If I had an office I would.
And the next time I buy a printer I look to linux-hardware-support first