The Previous and Next buttons are related to browse sequences rather than being a history of what has been viewed. Certainly those are the images that appear in the browse sequences in the RoboHelp Tour for my browse sequences. If a topic is not in a browse sequence, then they don't appear.
See www.grainge.org for RoboHelp and Authoring information
Richaa, you need to make sure you have created a Browse sequence, which is usually based on your TOC, and then in your Output settings, you need to select that Browse sequence in the output to include it in the help system.