Paul,
6 months seem like a bit long for this, but it sounds like google just needs to re-crawl the site. I don't know of any way to force a crawl besides building some high quality links that google can crawl back to your site.
I'd also recommend a google webmaster account. There are specific instructions on how to ask google to crawl a url - http://support.google.com/webmasters/bin/answer.py?hl=en&answer=1352276
Brian
