Hidden Control does not update with new value but label Control does

Okay, this is an odd problem and I do not understand what is going on here.

I have the following code contained within a loop.  I have removed alot of code that I feel is irrelivant but no where else within the loop do I modify hidInsCoID or lblInsCoId:
for (int i = 0; i < ds.Tables[0].Rows.Count; i++)
{
HiddenField hidInsCoID = new HiddenField();hidInsCoID.ID = Go to the complete details ...