There maybe a few things to consider and one is the type or types of responsive.css and .js scripts your theme is using as well as the setting mention by Ez on the blocks settings in the admin.
I check mine on Google tools and it tests great on the I-phone type mobile device and, also you can search the web for on line tools to test this. search for Mobile tests or something of this nature!
Even with the blocks disabled in the settings, you will still have issues with the SMF 2.0 + on some tables!
I'm working hard on, many scripts for responsiveness on some of my themes!
because I'm planning on using SMF 2.0+ vers, for a long while, but I'm also testing 2.1 beta 2 !