These notes don't show up on the print out for some reason. They are layered with another two staves.
Thanks for your help.
There is definitely nothing wrong with the part that you gave us. Does NWC print it correctly if you disable layering?
With layers you can get strange results if the layered staves don't have their bar lines on the same positions.
Maybe there are "missing" bars in one of the other staves.
You have solved the case. It was indeed related to missing bar lines in the "hidden" stave.