Text/Font semi corrupt?

Hello,

When I save my document as PDF, the part of the text becomes missing or "corrupt". There are only text layers and a background layer which is at the bottom of the layers so therefore could not be any of the text layers.

Please see the image here: help — Postimage.org

As you can see on the 'manufacturing' part of it is missing or outlined. This is only once I render it as a PDF. It does not happen as a JPEG, PNG or can see it in the PSD itself. My document colour settings are CMYK as it is for a brochure.

Any help is greatly appreciated!

Thanks