Mobile version?

I took the time over the holidays to bring my WP and P2 installs up to 3.5, with a child theme this time, all ready for future updates. Previously, using a mobile device sometimes we got the main site and sometimes a very nice stripped down version with a plain black header, no sidebars and just the posts. We’ve checked this on ipods, iphones and small Android tablets and a variety of mobile browsers.

This is my blog.

I was never able to tell what made browsers pick up one or the other version and sometimes it would vary between them on reload with no logic at all. Other users of my blog have confirmed the same effect.

Now that we’re on the latest software I was hoping this would resolve, but in fact what’s happened is that the mobile version has mostly vanished. On his android tablet, using the Dolphin browser, my friend says he can force the mobile version to load, but I can’t get it at all any more on my iphone using Safari, Opera, Chrome or even the iOS version of Dolphin.

Is there something else we need to do to make WP or P2 more responsive to browser detection? Is there a different something else we can do to generate a mobile version automatically at a different URL?