QTR-Quadtone RIP

Printing with linearized QTR profiles in CS3 works fine for me. When I print the same file in CS5 the dark values are off. I am consistent in my color management (all gray gamma 2.2) and print set up.
See this example using the supplied QTR  Ilford Smooth Pearl profile printing a 21 step wedge and reading LAB L with an Eye-One spectrophotometer. The red line is the print from Photoshop CS3, the blue line from CS5:
http://img40.imageshack.us/f/cs3vscs5.jpg/
Here is the Photoshop print dialog from CS5:
http://img821.imageshack.us/i/cs5printdailog.jpg/

I'd heard rumblings in the past about possible issues with printing in CS5 but my poor searching skills didn't turn anything up on this in this forum.

I can continue to print in CS3 but was wondering if there was a fix to enable using CS5?

Thank you!