KCModule integrating

Hello,
My program is to integrating some kcontrol modules into one own new kcontrol module, using KCModuleLoader.

Code:

---

MyKCModule::MyKCModule()
{ 
  ......
  KCModule *kcm=KCModuleLoader::loadModule( name, page );
  ......
  connect( kcm, SIGNAL( changed(bool) ), this, SLOT( moduleChanged(bool) ) );
  ......
}
......
void MyKCModule::moduleChanged( bool isChanged )
{
  ......
  emit changed( true );
}

---

When running, however, the "Apply" "OK" "Default" buttons are misacting or invlidating.
For example, if you change some settings, the "Apply" button still is gray and has no funtion.
Why?