Erratic font issues when publishing

Hi - I'm publishing a Japanese file and having some font display issues. Text is being arbitrarily bolded and unbolded in the preview and published files. The strange thing is that when I publish or preview just one scene, the text displays fine, with the bolding appearing correctly. However, when I publish the entire Project, everything gets messed up - bolding is taken away from where it should be, and also is getting applied to whole paragraphs where it should not. Desperate for some help here as this is due for delivery to a client. Many thanks for advise.