The problem occurs when you try to dynamically create poly areas which have different numbers of co-ordinates. Basically, if you have 2 poly areas, and the second one has fewer co-ordinates than the first, the 2nd area will crash IE6/7.

The fix is to create your IMG tag using innerHTML rather than DOM element properties.

ie this *won’t* work

var map_image = document.getElementById(’map’);
map_image.src = ‘images/maps/’ + map_file;
map_image.isMap = ‘ismap’;
map_image.useMap = ‘#layer’ + parent_level_id + ‘_map’;

Whereas if you put your IMG tag inside a SPAN, like so:

and update it like this:

var map_image_span = document.getElementById(’map_image_span’);
map_image_span.innerHTML = “”;

You should be fine.

I’ve notice this bug also. If somebody want to workaround it just use SPAN tag with IMG tag inside and in change map function assign innerHTML attribute with String <IMG src=’..’ usemap=’#someNewmap’>