The error appears universal for Chrome, Firefox, Safari, etc. I have repaired permissions, cleaned any caches I could find and so forth but the problem remains.
The problem appears also with externally loaded jQuery (for instance), returning in the case of jQuery the following errors:
$ is not defined (Firefox)
or
Uncaught ReferenceError: $ is not defined (Chrome)
Examples for websites that fail to load/run JS: reddit, omegle, www.translation-telephone.com.
What are some things I should try?
pingthese hosts or usecurlto retrieve the jQuery files in Terminal. If it fails, you should get a useful error message. Have you checked web developer extension (Firefox) or Safari's Develop menu for resource tracking functionality that could also provide some information? – Daniel Beck Jul 9 '11 at 8:16