Thanks Michael, that solves the issue. Bizarre default, though, because I would imagine most users would want to use art boards in exactly this way. No mention either that I could find in any of the documentation.
I've been a Quark user since the late 1980s, mostly for producing newspapers, books, magazines and newsletters. The beauty of Quark used to be its simplicity, but in recent times it's become bloated. Additional features have meant that some formatting options, previously achieved with simple keystroke combinations, have become more long-winded, not helpful in an industry working to tight deadlines, where speed is of the essence.
Two other areas where I feel Publisher needs attention is in colour handling and typographical default settings. I would like to see the Swatches palette developed to allow for the naming of colours so that they can be identified more readily. At the moment if you have similar shades in the same swatch it's difficult to distinguish one from another because of the tiny square of colours. I would also like to see the option of a default setting for leading, for instance, instead of having to set in every single Text Style.
Keyboard shortcuts are always important to smooth and efficient working and in my view Publisher doesn't at the moment strike the right balance with its shortcuts. Too many apply to little used options and not enough to ones users like me need.