google highlight

I've got this "google highlight" modifier which was taken from the wiki
http://smarty.incutio.com/?page=mod...oogle_highlight ta toma@etree.org

I've modified it slightly as per the link below
http://www.pastebin.com/272747

The only problem is that "ocassionally" some of the phrases return
spurious results..

eg -
search for "win do" is ok
<span class="google_highlight">Win</span>chester House.<span
class="google_highlight">do</span>c

however "pa ss" returns extra tags as
CP<span cla<span
class="google_highlight">ss</span>="google_highlight">Pa</span><span
class="google_highlight">ss</span>e<span
class="google_highlight">ss</span>ments

can a guru shed some light on this

tia

Pete