Hi all. I have a k2 module that is embedded in the footer of a site, it shows the last 2 "news" articles. All fine, but when I click on the news story title, it displays the story, but my custom header and footer, which are assigned to different menu items, disappear.

Is there a way to assign my normal "news" menu item to this module so that the header and footer and other bits, appear as they should?

I think you should do this in reverse, assign the module to the news menu item in the Menu Assignment section of the module.
Make it appear also in news by checking the "news" menu and saving.