Bizhub C8000 not printing some gradiented colours

[AB1984]

We have a job on at the moment which when imported to our fiery misses out certain gradients, unfortunately I can't divulge the client, or the rather specific artwork, but we have a gradient that goes from 0% C, 100% M, 60% Y, 55%K at one side of the page to 0% C, 100% M, 79% Y, 9% K at the other. But once imported to the fiery it just doesn't print. It does however show up on the 'preview'. I checked the preflight report,, and there are two things it May be, one Error saying 'check resolution is less than 150dpi', and there are 85 occurrences of 'overprint'. Could it be either of these, and if so, how would I go about rectifying it?

Many thanks

[Mick01]

Hi,
The only thing i can think of is to try turning "Composite Overprint" on. This may work.
Hope this helps

[AB1984]

I've just tried that...no luck I'm afraid.
Thanks for the help though

[AB1984]

I've just tried extracting a couple of the problem pages, the same thing happened again, but when I saved them as an 'optimized PDF' the troublesome logo appeared to print. So I do have a workaround now, but I would Love it if someone could explain why this works?

Many thanks