Not much help - but still helpful. I should add I am using a Mac with 10.5.5
Things have changed in CS4. If you printer drivers are not totally compliant with Leopard you will have problems. At least that is what we are being told.
Of course there is supposed to be 10.5.6 coming which is supposed to fix printing issues. ColorSync issues?
With my Canon iPF driver, with CS3 the driver settings defaulted to no CM and now with CS4 the driver setting default to ColorSync. There is no way to change either one. I am just glad we have a plugin to print from PS with the Canon printers, avoiding all the Adobe/Apple/Printer driver silliness.
Apparently if you running 10.4.11 there is no problem.
Doyle