Search has recently changed - hasn't it? It now outlines the word you are looking for in square brackets in the results.
I've also noticed it automatically searches for similar words e.g. swimming will also search for swim, swimmer etc. While it's helpful sometimes, at other times it's annoying as it's returning too many results and makes it hard to narrow down to something specific I am trying to find.
So could we either have this as an option rather than forced, or could we have support for quotes enabling an exact phrase search? :) Pleeease? 
BTW I know I could use google for a phrase search but I like the mumsnet search function, the ability to search different sections etc.