C# Not Disposing controls like I told it to...

Answer 1

Dispose() only cleans up unmanaged resources (although Paul Williams noted in the comments that it is usually more complex than this!) so it may or may not do anything useful in your case.

Try removing the controls with the RemoveAt(i) method, not Dispose():

for(int i = panel.Controls.Count-1; i >= 0; i--)
{
    panel.Controls.RemoveAt(i);
}

Answer 2

A simpler way to delete all your controls is to do this:

panel.Controls.Clear();

Answer 3

I have seen this before, you are removing items from acollection that make the collection itself smaller. e.g if there are 5 items in the collection as you move down through it you come to the end of the list sooner than you expect because the list gets smaller with every Dispose() you issue.