I've tried the plugin on a couple of different installations and it works brilliantly, except that the column spacing keeps resetting to 0%.
I set the width, press update, it saves, i look at the page live, looks good. Then i click out to edit another page and without even going back to edit the column page if i go back to the live view the columns are not spaced out anymore. If i go back to the editor page then the spacing is now 0%?
Strange, somehow it is not saving correctly or it is being overwritten.