I have the following google maps code:
IE doesn't like "hanging commas" (commas at the end of arrays or objects, without anything after them). They cause it to append a null to the end of the object or array, which then generates an error in the API.
Remove them from your code.
var beaches = [
['Car:806', -27.4481025666613, 153.035155217002, 916],
['Car:520', -27.4777186625335, 153.00697421394, 915],
['Car:1477', -27.4523199466005, 153.029570366226, 914],
['Car:815', -27.5315143182514, 153.023819055977, 913],
['Car:334', -27.3930054770139, 153.104887341157, 912],
['Car:191', -27.4705744176833, 153.030243260862, 911],
...
['Car:618', -27.4146792620242, 153.081801794924, 1],
['Car:1096', -27.3369540394594, 153.069279763313, 0], // ** remove the comma at the end of this line **
];