Turns out there's a maximum limit on setInterval after which it will fire immediately, rather then what you expect (which is to never fire) on chrome/firefox.

gistfile1.js

var a = function() { 
    alert('bang!');
}

var signedIntMax = 2147483647;
var signedIntMaxPlus1 = signedIntMax+1; // will cause bang immediately on webkit/firefox but not IE

setInterval(a, signedIntMaxPlus1);