Yes, as noted by jcl in that thread, it will be corrected in the next version, meanwhile you can correct yourself the code. This is the correct one:

Code:
// Simple ATR based on SMA
var ATRS(int Period)
{
	Period = max(1,Period);
	var vATRS =  0;
	for(g_count = 0; g_count < Period; g_count++)
		vATRS += priceHigh(g_count)-priceLow(g_count);
	return vATRS/Period;
}