FormAPI & cgi-callout question

System

Hello,

I have a text item in my DCT for storing a date which is entered using a cgi-callout. I've made this item read-only using:

var publish_dateItem = IWDatacapture.getItem("/publish_date");
publish_dateItem.setReadOnly(false);

When I change the value of this item using the callout, this is not directly shown on form so I suppose I need to redraw the form. To do this I registered an item handler:

IWEventRegistry.addItemHandler("/publish_date", "onItemChange", publishDateChange);

and implemented publishDateChange():

function publishDateChange(item)
{
alert(item.getValue()); // TEST
IWDatacapture.redraw();
}

The problem is that the event handler function does not fire when the item's value is changed by using the cgi-callout! Any ideas?