Solution for Canon LBP2900 with Snow Leopard
http://support-au.canon.com.au/contents/AU/EN/0100253902.html
Here you can find new version for CAPT-driver which fixed my previous tries to follow Dexters good guide to replace Canon printer selection.
Regards
zacce
MacBook Pro, Mac OS X (10.6.8), Canon LBP 2900 problem solved