When I opened my spot color plus black file to see why the printer tells me it is coming through as a CMYK file (InDesign ver cs2 converted to pdf file), I saw that Indesign had converted the spot color to cmyk and would not go back to spot color as all previous versions have had. When I opened a previous file in case this file had corrupted the color, they too showed cmyk. Taking out a picture (photoshop jpg grayscale) printer told me was coming through as CMYK and sending it separately so he could fix that on his end, and sending the file with PMS 362C spot color replaced by cyan to achieve two plates only also resulted in him receiving a cmyk document. How can we fix this fast? It isnow a day overdue.
I don't have a CS2 installation, but in CS3 or later spot colors would get converted to CMYK via Ink Manager (Swatches>Ink Manger>All Spots to Process)