We were working on adding a mobile theme to the site one day and I had to do a double-take. All was good, we installed WPTouch mobile theme/plugin and it look fantastic on the iPhone. Then I got the call – hey, the live site looking funny in IE> I replied “what’s new IE always looks funny” – but what had happened was the WP3 Total Cache had done its job and cached the mobile site. We quickly disabled it – and found a soution.
Sometimes mobile and caching do not mix – but after reading a post over at the WordPress forums, there is a good fix. I tried this method out – and it worked grrrrrrreat.
Good luck – email me if you have issues – it was a quick fix.