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I think I've found a bug in IE's (IE8) handling for the for-in javascript statement. After several hours of boiling this down to a small example, it looks like IE specifically skips any property called "toString" in a for-in loop - regardless of whether it is in a prototype or is an "Own Property" of the object. I've placed my test code here : function countProps(obj) { var c = 0; for (var prop in obj) { c++; } return c; } var obj = { toString: function() { return "hello"; } }; function test() { var o = ""; var d = document.getElementById('output'); o += "<br/>obj.hasOwnProperty('toString') == " + obj.hasOwnProperty('toString'); o += "<br/>countProps(obj) = " + countProps(obj); o += "<br/>obj.toString() = " + obj.toString(); d.innerHTML = o; } This should produce: obj.hasOwnProperty('toString') == true countProps(obj) = 1 obj.toString() = hello but in IE, I'm getting: obj.hasOwnProperty('toString') == true countProps(obj) = 0 obj.toString() = hello This special casing of any property called 'toString' is wrecking havoc with my code that tries to copy methods into a Function.prototype - my custom toString function is always skipped. Does anyone know a work-around? Is this some sort of quirks-mode only behavior - or just a BUG?

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