We have the same problem but we use an HP DesignJet 800PS. We've checked and unchecked Quartz imaging, print patters at on-screen res, rasterize, hardware accelerated 2D nav. We downloaded the newest print driver and printer firmware. I spent a day on the phone with no final solution. Anything else we can try?
Some of the solutions above got the patterns to print in the full area but then they wouldn't be the same patterns as what was on the screen, so it's either the wrong pattern or a small portion of the correct pattern.