I've found the solution for my printer, and I hope it works for others...
I went into Systems Preferences, and clicked on Print & Fax. There I saw my Canon i9900 listed under "Kind:" as "BJC-8200 GIMP-Print" Not knowing what a GIMP-Print was, I Googled it and found the following web page:
http://gimp-print.sourceforge.net/MacOSX.php3
The page pointed to an updated Gimp-Print driver, which is now called Gutenprint. They describe it as follows:
"Gutenprint 5.1.2 is a development release of Gutenprint 5.1. It is based on Gutenprint 5.0.0. This is the first Mac OS X release to contain several new features: Shrink the output necessary to fit the imageable area of the page. Crop the output if necessary to fit the imageable area of the page. Expand the output to fit the maximum possible imageable area of the page. It also contains support for many more printers, improved quality, and enhanced functionality. Mac OS X Jaguar users need ESP GhostScript for full support. ESP Ghostscript is not required for users running Mac OS X "Panther" or later."
Note that this driver is for Mac OS X (10.2 and later), specifically for Canon, Epson, Lexmark and PCL printers. If you're using one of those brands, the download may work for you. It worked for me, and I can now print on the entire page (
brilliant!).