Tweets disappear when page is refreshed

I have installed twitter block using the Surreal theme - but when the page is refreshed the tweets disappear and I am left with just the block title and twitter user. The tweets only "reappear" after several hours. Clearing the cache doesn't make a difference.

The only way to clear this in chrome is to go to admin/config/performance uncheck all the bandwidth options then clear caches. Then when you return to the page with the twitter block the tweets appear. If you reload the page again they immediately disappear again.

I get the following error message "widgets.js,qnhuxqv.pagespeed.jm.Pa9oUAjwWG.js:1 Uncaught SyntaxError: Unexpected identifier"