Closed Issue: 3 cascading dropdowns SelectedValue doesn't work for #3 dropdown [17378]

I have a page where I have 4 cascading dropdowns
I set their value server side like this
StateCascadingDropDown.SelectedValue = Item.CityRegion.City.StateRegion.State.Id.ToString();
StateRegionCascadingDropDown.SelectedValue = Item.CityRegion.City.StateRegion.Id.ToString();
CityCascadingDropDown.SelectedValue = Item.CityRegion.City.Id.ToString();
CityRegionCascadingDropDown.SelectedValue = Item.CityRegion.Id.ToString();
But the only first two dropdowns are populated.
After some investigation I found that it looks like #3 and #4 are not populated becasue their parent list is not yet ready or something like that.

It populates all controls fine when I set a breakpoint in FireFox on line #514 (set_SelectedValue : function(value, text) {) so I suppose a race competetion between child controls is the reason of the incorrect behavior.

Thanks
Comments: This ticket was filed for a pre-15.1 version of AJAX Control Toolkit. If this is still an issue in v15.1 or later, please file a new issue.