I have the same problem (bad JSON most of the times). The weird thing is that if I access the URL direct from the browser it works (good JSON every time). I'm using jQuery.getJSON and I think that this (or something connected to this) might be the problem.
Unfortunately I cannot use window.onerror (as Michael suggested) because I have multiple asynchronous requests at the same time (it would be tricky and expensive to find out which one is bad - at least I suppose so). Good luck in solving this -- Twitter developer documentation and resources: https://dev.twitter.com/doc API updates via Twitter: https://twitter.com/twitterapi Issues/Enhancements Tracker: https://code.google.com/p/twitter-api/issues/list Change your membership to this group: https://groups.google.com/forum/#!forum/twitter-development-talk