I hear ya Its happening in Parallels though. MAC side works great. Gonna keep playing and see if I can figure it out.
Works fine for me with Win 7 64bit running in VirtualBox. But I don't print anything near the size of your prints.
I know that changing print spooling options was needed when I first set up, over a year ago. Incidentally, my photographic printer is attached to a Linux Box on the LAN.
Peter