Looping through Controls in inherited Form...

So I'm having a relatively simple task of looping through all Controls on a Form, something I've done many times before without troubles. This time I do have a problem though. The Form I'm passing to my function has a base Form which already has some Controls on it. Now the problem is that my function only loops through the Controls on the base Form, ignoring all the Controls I added to the current Form.
The function I'm using to loop through the Controls on my Form looks like this:

public void LoopThroughControls(Control parent)
{
   if (parent != null)
   {
      foreach (Control ctrl in parent.Controls)
      {
         this.LoopThroughControls(ctrl);
         // Do something with Control here...
      }
   }
}

I use this from within a Component and I get my Form as follows (copied from the System.Windows.Forms.ErrorProvider Site Property):

public override ISite Site
{
   get { return base.Site; }
   set
   {
      base.Site = value;
      if ((value != null))
      {
         // Try to get the IDesignerHost (the Form of the current Component)
         IDesignerHost host = value.GetService(typeof(IDesignerHost)) as IDesignerHost;
         if ((host != null))
         {
            // With the IDesignerHost it is possible to get the RootComponent.
            // This is the Form for the active designer.
            IComponent rootComponent = host.RootComponent;
            if (rootComponent is ContainerControl)
            {
               // If the RootComponent is a ContainerControl we assign it to the ContainerControl Property.
               this.ContainerControl = (ContainerControl)rootComponent;
            }
         }
      }
   }
}

I then call the LoopThroughControls function passing in ContainerControl as parameter. When I set a breakpoint I can see all the Controls in ContainerControl, but they are ignored when looping through the Controls.
When I call the above function directly from my derived Form is DOES loop through ALL Controls. However, ContainerControl seems to have a reference to the derived Form as well, so I can't really see the difference...
So anyone has an explanation, and even better, a solution?

Tags: C# (C# 4.0), .NET (.NET4), Windows Forms, Inheritance