It stayed around 250,000 pages for about 6 months but today were back down to 9000 pages in the Index.

Oh, to answer your question here is the info in google webmaster tools:
Total URLs in Sitemap: 741112
Indexed URLs in Sitemap: 226165
And each of my sitemaps have a warning which says:
All the URLs in your Sitemap have the same priority.
All the URLs in your Sitemap are set to the same priority (not the default priority). Priority indicates the importance of a particular URL relative to other URLs on your site, and doesn't impact your site's performance in search results. If all URLs have the same priority, Google can't tell which are more important. Problem detected on: Apr 25, 2009
All the URLs in your Sitemap are marked as having dynamic content.
All the URLs in your Sitemap are marked as having dynamic content (the value of is "always"). Because dynamic content is difficult for search engines to crawl and index, this may impact your site's performance in search results. Check your Sitemap to make sure your site information is correct.
This might have something to do with it.?.?