Further Search - uses relevance instead of default property for sorting

Hello gurus.

We have defined the search components and are using a standard KM search iview, enabling sorting of search results and enabling further search after a quick search. Default property for sorting is defined as publication date. No problems sorting search results. But when after one search the user starts another in that same window (not the home page), instead of using the default property publication date, it uses relevance. Relevance being the first displayed property of the collection renderer. Why doesn't it uses the publication date for sorting here? Help please.

Mahaly