Printing gradients in cmyk PDF saved from illustrator

We have a particular job that needs to be CMYK printed that has a gradient between 2 solid colours. As you will see in the first image, the colours are fine in illustrator but when saved as a PDF and imported into our rip program Versaworks 6, it appears that the gradient changes to a neon appearance like I've imported a RGB file as you'll see in the second screen shot.

The gradient has been created by eyedropping colour from the circles on each end so it should match. It also prints differently so the colours are noticably different in the end result. 

We've tried flattening the gradient, recreating it, saving it with different settings but the only thing that seems to work is saving it from corel which is a problem.

(please ignore the pixelation and orientation of the second image as thats the view we get in Versaworks.)

Can anyone tell me if this is a PDF setting that needs changing or something that needs to be done in the creation stage of the artwork?