DesignJet 800

I guess this question is 2 fold.

I have a DesignJet 800 printer and when trying to print an Adobe Illustrator file it prints approximately 75-80% of the file and then “thinks” it is done. It doesn’t give any error messages, just feeds the rest of the sheet without printing and cuts it off where the page would end (at least it appears that way).

Part 2:
My first inclination is that it needs a postscript driver, however HP does not have one. They actually have an entire different printer (DesignJet 800ps) which costs $1300 more. Is it possible to upgrade the 800 to an 800ps or is there somewhere I can get the PS driver for the 800?