Turns out there were some problems with the mesh that were fixed when I ran the STL through netfabb. A little confusing how it would only fail sometimes though...
Slices without a problem now!
Been running into an issue occasionally where the preview mode will show these gaps in certain areas of the model (see attached). Strangely enough, I can sometimes manage to correct it by re-slicing the model. I haven't tried printing when the gaps are shown, as it does skip over those parts when I ...