After developing and testing a mobile view for a site, I uploaded it to the live server and gave it a quick test. Loading it up on my iPhone the mobile view loaded as expected, but none of the jQuery features were working, as if the jQuery file hadn’t been uploaded.
can't find variable $
as if jQuery had not loaded, it also indicated a parse error with the jQuery 1.7.1 min.js file.
I found restarting Safari solved the problem. Random.