thanks for the reply eric.
in my original post, it was the additional code i was having a problem with.
changing the parameter as i mentioned has resolved this part.
the only issue I now have is the tags which are saved along with the text in html editor.
whilst looking at the source, i can delete these tags, but i wondered if i could do this programatically on the instances where i was editing the meta tags.
i also wondered if these paragraph tags within the meta tags have an effect on how keywords / description / title are read by search engine spiders ?