Random blank pages when looking at pages

I have upgraded to 3.5 and 3.5.1 now the alpha of 3.5.2 to see if it will resolve my issue.
Going to my site it will randomly show just a blank page when switching to pages.
On an iPad you can press the reader button and content is there so it’s loading but not displaying.
Switching themes to another does not display this issue. It was at the same time my header now only displays one color (blue) that this started to happen.

Sometimes you can click refresh (anything up to 6 times so far) on the page and it will appear, other times simply nothing.

I have switched on the theme and the site is http://www.frequencyhurtz.com.au if anyone wants to take a look at the issue?

Thanks
Thomas