There is no reason to believe that anything about b2evolution makes your web un-friendly to search engines, so lets look at some basics. Where is your blog? Got link? How old is it? Have you seen any indexing from any search engines in your stats? Are you sticking your blog in a frame?

BTW even the "cosmetically unappealing" urls (with all the &param=value stuff) gets indexed by most search engines. People don't like them because they can't read them, but search engines don't care. A link is a link and a page is a page, but a frame is a mistake.

Oh do you have a robots.txt that is stopping the good engines from finding your blog pages? What about anything wierd in your .htaccess (if you play with that at all)?

How long has your blog been up? Have you submitted the URL to the search engines? It takes some time (possibly weeks) for some engines to actually spider your site after you submit it, and could be even longer for them to find it on their own.

Mine was found by Google without any changes, and I didn't even submit it.