If you look at the gmail ajax calls, you'll also see they sometimes put a number in front of their data. Example: 3 [1, 2, 3, 0] If you execute that in your

If you look at the gmail ajax calls, you'll also see they sometimes put a number in front of their data. Example: 3 [1, 2, 3, 0] If you execute that in your JS console, it'll return undefined, which threw me for a loop a couple days ago when I saw it. I ended up having it ask on StackOverflow too and it's because JavaScript will interpret it as a property look up on that number object (it will evaluate to 3[0], which evaluates to undefined).