Your options are pretty much this:
-resort to "unsavory"
SEO techniques (I would discourage this)
-do an alternate HTML version of your site (time consuming)
-stop using flash (the "flash haters" will preach this one)
-place a simple HTML footer navigation area at the bottom of your site
-make a static, HTML only site map with links to each of your content pages, the one you have now uses flash
In your case I would reccomend the last one or maybe the last two combined. The sitemap doesn't have to be pretty. 99% of your visitors will never look there, and if they do, they will appreciate the utilitarian "feel" of it.
An example of how I do this for most of my sites is
here. It looks nothing like the rest of my site, I had to do it before I discovered the wonders of mod-rewrite to cure dynamic URL's, and have been doing it ever since. It's ugly, cold, and pure function, but the SE's can find what I want them to find now.
Hope this helped.