Strange behaviour on search results title

Hi all, recently discovered atahualpa and loving it. Found it easy to learn and use.

I just have one strange thing happening. The best way to explain it is to perhaps ask someone to visit my site Just Shop and Give and do the following:

1. Click the 'Art' category from the list on the left - Push Posters should be the first in the categroy -everything is fine!
2. Now enters posters as a search term in the search box above the categories - hopefully it's obvious what my problem is - why has the post title gone wrong - is there somewhere to edit the search results page?

Thanks very much for any guidance,
Nick