My inference is that "bi-directional" is equivalent to "high quality - uni-dir - slower" vs "standard quality - bi-dir - faster".
Some questions:
* What software are you using to make prints? PS? LR? Generic?
* What O/S? (XP, Vista, Win-7, Win-8, other?)
* Can you switch between "High" and "Standard" quality in the print-driver?
* Is this an original 9000, or 9000-2? What is your "other Canon printer"?
* Can you provide a screen-print of the dialog where this is occurring?
* What is the "media type"? Plain paper? Glossy? Matte? Fine-art? Some options may not be available for certain media-types.
HTH