I tried OpenSEF & Artio JoomSEF prior to this one. This one actually works. Try this one first and save yourself some hassle. Although the UI looks strikingly similar to Artio, it doesn't come with the adware. That's right - the free version of Artio buries advertisements for itself in your meta tags. If you're not into that, there is a hacked version by some Kangaroo company on here you can try. I had the same problem with those - it didn't consistently fix URLS. On the same page I'd have /article/birdfeed.html and for the readmore link it would re-write it to /article/birdfeed_2.html What's up with that? Try this module to avoid issues.