Working on JSCSSP, I have discovered a rather big issue in string manipulations in IE's javascript engine. Tested with both IE8 and IE9 Preview. I don't have IE7 handy. In some cases, str[i] where str is a string and i a valid index in the string fails and returns "undefined". Extremely strange. String.charAt() still works fine. I've pinged Microsoft about it and they're now working on it. I am currently trying to narrow the bug even better.

Update: I just found the potential root of the bug. I am waiting for MSFT's ack to let you know. Stay tuned