Lawrence, you are going to as familiar with Photoshop idiosyncrasies as most of us, but isn't is still likely to be an issue with the print driver? Have you tried changing the print settings, like Printer manages colour etc.? What printer are you using?
BTW 8.5 is news to me. I'm slightly surprised at an upgrade being released so close to the big June 18th updates.
Adobe Camera Raw 8.5 and DNG Converter 8.5 release candidates available: Digital Photography Review