Hey James
Are you tracking your keywords within Google US? Moz replied to my email telling me the following:
'I am so sorry for the confusion! Right now, we are only able to provide this data for campaigns that are tracking Google US as one of the three search. We are working on a solution to this issue for campaigns tracking other search engines locales, most likely on English language locales, but I'm afraid that we don't have an ETA for when that will be available.
I know this isn't clear in the app. Unfortunately, there was some miscommunication when the feature was launched and it was made available to all campaigns, rather than to only campaigns tracking Google US. I sincerely apologize for that error! We are working to roll the launch back on campaigns that are not eligible until we are able to add the feature for other search engine locales.'
So basically it is only available for keywords being tracked within Google US!
Cheers
Alex