Trying to print from Windows using Parallels 4.0 under Mac OS X Snow Leopard and getting the infuriating and useless error message “pstopdffilter/pstocupsraster failed with err number -31000″?
I spent a fair while Googling for a solution to this before stumbling across the answer: turn your printer off and back on. That’s it. No reinstalling drivers, adding or removing printers or playing with settings – just a good old fashioned power cycle. It’s nice to know some things never change 
Hat tip to Walt-O-Matic for the answer.
I was printing from Microsoft Office Word, via a networked HP C4480 printer on Windows Server 2008 via an Airport Extreme.
Turning the printer off and on did not completely solve the problem for me, but it got me started on my own work around below. First, I installed the latest Epson Stylus Photo R300 drivers for Snow Leopard (from Epson website) and when I turned the printer off and then on again I get a Message Window that says a new USB device has been detected. “Do you want to use it for Mac or Virtual Machine?” When I select Virtual Machine (meaning the Windows side of Parallels) I could print checks from my Quicken program. But then I could not print e-mail or web pages from iMail or Safari on the Apple side. When I went to the Apple Print Monitor, I saw the print job was in the queue with the message “Waiting for Printer to be available”. So I turned my printer off and on again and got the same message about a new USB device being detected. This time I hit Mac and as soon as the printer went through its startup cycle the e-mail in queue began printing. (I never had to do this before.) So apparently Parallels has a problem recognizing printer when you associate it with the MAC and you have to use this little work around until they solve this interface problem. It’s a pain but at least I can now print my Quicken checks which is running on the Windows side of Parallels. Hope this helps somebody.