Everything working fine, except the width of the table produced by the shortcode. Using 'Inspect Element' (Chrome), it looks like the width is set to 100%, but this is translating into a table 4273 pixels wide!
I've successfully changed colours in the table using CSS (set the header row background to transparent), but can't find what's wrong with the table width.
The theme I'm using is Headway 3.2.5 - this has a 'live' CSS editor, so I don't have to mess with the original CSS files.
Thanks for your help. David