I think its a simple question of knowing how to use the whizz wheel, and how to plot accurately on da map! Also know about ure radio nav aids. The only question I got wrong was to do with the relative bearing to the ADF due to drift!! It is nothing to worry about even though most people (including me before I took it) feel that it is one of the harder ones! Oh and the PPL Confuser helps if you have it!!
Tom