I have created a custom section for umbraco. It works great except for the delete part

I have library called "sector.dll" With a classed called sectorTasks. In the class I have the following code

namespace Sector
{
public class sectorTasks : ITaskReturnUrl, ITask
{
// Fields
private string _alias;
private int _parentID;
private string _returnUrl = "";
private int _typeID;
private int _userID;

// Methods
public bool Delete()
{
throw new Exception("Delete Method");
return true;
}
}

the ui.xml has the follwiing

<nodeType alias="initsectors">
<header>Sector</header>
<usercontrol>/create/createSector.ascx</usercontrol>
<tasks>
<create assembly="sector" type="sectorTasks" />
</tasks>
</nodeType>
<nodeType alias="sectors">
<header>Sector</header>
<usercontrol>/create/createSector.ascx</usercontrol>
<tasks>
<delete assembly="sector" type="sectorTasks" />
</tasks>
</nodeType>

But for some reason it newer hits the delete.