script is not running on 10.5.2 but run on 10.6.6

automator workflow is here on https://docs.google.com/leaf?id=0B3LLTktA3cleN2VhMGQxNjUtNzAzMi00NGRiLWE5OTctMTA2MjFlOTY5OTU1&hl=en_GB

this is automator workflow run on 10.6.6 but gives error on 10.5.2 as : The action “Find Finder Items” could not be loaded because it could not be located.