Starting with r11826 there are problems with Bug689369.pdf and Bug690022.pdf with the psdcmyk device. I've attached a couple of png files showing scaled down output (the left image is r11826, the middle is r11825, and the right is the difference). The command line I'm using: ./bin/gs -sDEVICE=psdcmyk -o test.psd -r72 ./Bug689369.pdf
Created attachment 6820 [details] tests_private__comparefiles__Bug689369.pdf.psdcmyk.72.0.page_1.png
Created attachment 6821 [details] tests_private__comparefiles__Bug690022.pdf.psdcmyk.72.0.page_1.raw
Created attachment 7018 [details] tests_private__comparefiles__Bug689369.pdf.psdcmyk.72.0.page_1.png r11923 changed the Bug689369 psdcmyk output but it's still wrong (see attached, left is current, middle is correct, right is diff). The other file that broke with r11826, Bug690022.pdf, didn't change.
Both files render correctly in the latest version. I have no idea what fixed this, but it all seems fine now.