Thanks for your prompt reply. It seems to have fixed the layout slightly but I am still unable to get rid of the viewport.
For example if you type in 'adm' in the search box there are 3 results, 2 under Course, 1 under Industry. No matter what I seem to do, the viewport is always too small for the results and a scroll bar is used.
I can confirm this is an issue with Grouping, as when it is turned off, no scrollbar is shown.
Thanks for your help in advance.