Digital BW, The Print

I have noticed an issue with applying the curve to images opened out of Lightroom into Photoshop. There is apparently some kind of color information in the file that corrupts the curve, or at least causes it to display and function improperly. The following steps resolve the issue: 
 
When your grayscale conversion is complete in Lightroom, right click and open the image in Photoshop. Convert the file to grayscale using the Image>Mode commands. Save the file  (as a .tif or .psd) and close it. Reopen the file from within Photoshop and convert it back to RGB mode. The curve will now apply correctly.  
 
The symptoms of the problem are this: When (the warm) curve is applied, it should turn the blacks deep blue and the mid tones shades of purple. Straight out of Lightroom, the image will have blacks as black and the tones of gray are shades of purple. Printing, when the image is in this mode, will have overly dark blacks and significant surface issues. With the file-save and re-application of RGB, the image prints correctly with no surface defects.