Ugly Safe Title error code :(

I have introduced safe title to my word press site, and on this page:
http://simonbailey.co.uk/archives/star-kokopelli/#respond

I get this ugly error message:

Warning: Missing argument 3 for tguy_st_strip_if_in_tag() in /mounted-storage/home3/sub006/sc10962/www/wp-content/plugins/safe-title.php on line 51

Any ideas how I can fix this, and what the problem is?

Thanks in advance