Usually participants selected 'custom animation' either as Item of the slideshow
menu or of the bottom toolbar.  'Custom animation' then opens in the right
taskbar, which the participants usually did not realise.  Instead, they
recognised the entry 'Custom animation' in the right taskbar and selected it.
This closes the previously opened 'Custom animation' and opens  'slide
transition', which leads to confusion or even remains unnoticed. 
Recommendation: Make it more obvious what section of the task pane opens by
animating the open/close phases and slowing them down. Improve the design of the
sections' separators. Leave all sections closed as the default and use the free
space for a brief description of the task pane and its relation  to the current
view.

Keyword: ux-ctest