Error when trying to use 'Customize' with WP touch and Gantry 4 framework

I am trying to create a mobile theme for my site, and found when I try to go to the ‘Customize’ option under appearance, I get a server error message. If I deactivate my Gantry 4 framework, I can work on the mobile theme in the Customize option, but this shuts down my site. So it would be nice to work on my mobile theme with the site live.
Any way around this? I have tried this solution offered here but it did not work for me.