I have a mac running OS X.7.2 and Firefox 9.0.1. My printer is a Canon MX310 inkjet black and color. My default printer setting is black in the mac print utility. I have issue printing from Firefox only. It won't print because it says it must print in black and color when my settings are black only. I reinstalled FF and reset printer settings to default to no avail. I had to change my mac profile to "black and color" with FF closed and now printing away in color, Yikes ($$!).