John,
I have similiar problems with my HP9000. I've done everything that's been suggested. Been on the phone for hours with HP also.
Try this, I've found this works the majority of the time: Try "file" then "Print". Make sure the check box for "run locally" is checked.
I've been told doing this allows the PC to rip most of the document and puts less strain on the printer.
Also, have you tried using the image downloader. Download the images to the printers hard drive, then just use a call. Thats also worked. I believe you'd find those instructions in using Dynamic Images section of the book.
The problem I have found with the HP9000 is in the printers ability not in PlanetPress.
Just FYI My 9000 has 390megs of Ram and a 20gb HD. Still have problems like that.
Eric