Hi all:
It's working now. !!!
Let me share with you more specific details.
I have some users in my iMac. This time, I used the Full Access user (administrator)
A.- First time I used to uninstall printers but the last time I use Print Service Reset (This uninstalled all my printers and scanners)
B.- RESTART
C.- I followed the original instructions as follow:
1. Download and install the following driver (version 3.67 has just been released for Yosemite): http://support-au.canon.com.au/contents/AU/EN/0100420705.html
2. Restart computer.
3. Download and install the patch appearing at step 3 on this page: http://macdaily.me/howto/how-to-install-canon-lbp2900-on-mac-os-x-mavericks/
4. Restart computer.
5. Connect the printer with USB, add the driver in Printers and scanners preferences, select the appropriate driver.
6. Enjoy the rest of the day.
D.- I reinstalled my Canon Scanner once again.
Everything is working now as expected.
Thanks a lot to all of you
Really appreciated.
Molinatrix