Hi Alan,
It's not uncommon for Bing/Yahoo to vary in search results from other search engines, but the scope of the difference you describe does seem a bit odd.
Although I can't tell you exactly why it isn't ranking there are a few things we can look at:
1. The site is in Bing's cache. That's reassuring. And the last crawl date was pretty recent.
2. To analyze problems, I'd check the site through Bing Webmaster Tools. If you don't have a Webmaster account, I'd take a few minutes to set one up and verify your website. Once you do this the webmaster suite has several diagnostic tools you can take advantage of.
- SEO Analyzer
- Link Explorer - Enter your URL and see if Bing has indexed links to this particular page
- Fetch as Bingbot - See if the Bing crawler discovers any issues when crawling the page
It's pretty common for Bing/Yahoo to index far fewer pages than Google, and indeed you can see the huge different numbers reported for your site
Which seems like a really big difference. Bing does a pretty good job of removing low quality pages from its index, but I can't be certain that's what happening here. It might be worth a look to see what pages are being indexed, what ones aren't being indexed, and finding out what the difference is.
Regardless, hope this helps, if only a little. Best of luck with your SEO!