IE7/8 javascript "SCRIPT5007: Unable to get value of the property"

I've got a site under development which uses Google Maps API V3 to load multiple location makers. Everything is working except in IE7/8 where my looping through an array fails due to the following error: ``` SCRIPT5007: Unable to get value of the property '5': object is null or undefined ``` I've looked through all similar questions on StackOverflow and can't find any solution. So I'm trying to access data from an object array (I also tried a nested array but the same error occurs). My array is as below. I have also tried dropping the html object in case that was causing an issue, but no change - IE7/8 still can't get the object value. ``` var sites = [ {title: "Hermitage Medical Clinic", latitude: 53.3593139774, longitude: -6.40494071541, enumerator: 1, html: "<div class=\"find_a_surgeon_info_inner\"><h4 style=\"margin: 0; padding: 0;\">Hermitage Medical Clinic</h4><p>Old Lucan Road, Dublin 20</p><p><a href=\"http://devel.pixelapes.com/iaps.ie/location/hermitage-medical-clinic/\">View hospital details</a></p></div>", iconTerm: "hospital" } ]; ``` And here's my function which is trying to access the data: ``` function setMarkers(map, sites) { for (var i = 0; i < sites.length; i++) { // var sites = markers[i]; var icon = '<?php bloginfo("template_url"); ?>/images/map-icons/' + sites[i].iconTerm + '.png'; var siteLatLng = new google.maps.LatLng(sites[i].latitude, sites[i].longitude); var marker = new google.maps.Marker({ position: siteLatLng, map: map, icon: icon, title: sites[i].title, zIndex: sites[i].enumerator, html: sites[i].html }); var contentString = "Some content"; google.maps.event.addListener(marker, "click", function () { infowindow.setContent(this.html); infowindow.open(map, this); }); } } ``` I've also tried dropping back to just using the default Maps marker in case there was a specific issue with the iconTerm object but IE7/8 just fails trying to get the next object value. Here's a page on which this is occurring: http://devel.pixelapes.com/iaps.ie/surgeon/eamon-s-beausang/ Strangely, I have another map instance where I'm not setting the bounds with map.fitBounds. The failure to get object values still occurs but the map sort of loads (but very messily): http://devel.pixelapes.com/iaps.ie/find-a-hospital-or-clinic/ I have tried removing the fitBounds functionality on the single surgeon page but the map still doesn't partially load as it does on the "Find a hospital" map. Any ideas on how to get around this?