[altworld]

You have to check out Word PDF engine you set it up in preferences to make sure it outputs all images at 300dpi. The default is 150dpi - if you cannot find the controls see if you can force them by selecting the PDF to print and working the settings in the print window.

Depending on the image and size Createspace will print it fairly well as they use a Digital press to print your pages and not a traditional litho printer where dpi becomes much more important as it refers to the dots on the films (that make the plates.)

I've had images down to 72 dpi and they came out fine.