Graham, I am not sure if this will be any more help. I use Epson printers and don't print from Lightroom, but this is what I
would do in Lightroom print module (its very similar to printing in CS3):
1. Print Job section (righthand panel): uncheck Print Sharpening (I would apply this in develop myself)
2. Print Job section (righthand panel): Color Management->Profile - select the correct profile for the printer and paper I am using
3. Print Job section (righthand panel): Color Management->Rendering Intent - select Perceptual
4. Click "Print Settings" button (bottom of righthand panel): Select correct printer, paper size. Click the Properties button.
5. In advanced options I switch off Color Management (usually refered to as ICM), ensure that quality and paper are correct (high quality, not high speed, correct paper for the profile I selected above) - note that this is printer specific, I am not familiar with the Canon terms.
6. Click OK on the two open dialogs
7. Press the Print... button and hit Properties to check everything before clicking OK!
BTW, what operating system are you using? If it is Windows, then a little application needs to load the monitor calibration at startup. Normally this app is installed when you install the calibration software.
However, if you already had Adobe Gamma or similar installed, this can 'fight' with the new software and lead to colour casts on your images (Magenta for example...).
You can check by looking in Start->All Programs->Startup where you will see Adobe Gamma (if it is present). Easiest fix is to uninstall it using the Add/Remove programs dialog in Control Panel and reboot.
If you are on a Mac, I haven't a clue