Problem with initialising

Hello,
I'm a beginner and I'm trying to use MyGUI system. But I can't get it working. After I call

mGui->initialise(mWindow);

it will fail. I've found out where does the error come from but I don't know how to fix it. The last thing that is executed is in MyGUI_LayerManager.cpp on line 31, that's where it crashes.

...
Gui::getInstance().registerLoadXmlDelegate(XML_TYPE) = newDelegate(this, &LayerManager::_load);

// Line 31:
Ogre::SceneManagerEnumerator::SceneManagerIterator iter = Ogre::Root::getSingleton().getSceneManagerIterator();
if (iter.hasMoreElements()) {
...

I put MyGUI initialisation after the Ogre Root init. and SceneManager init.
And this is what I get when debugging line 31 (in Visual C++ 2008 EE):

// mouse over Ogre::SceneManagerEnumerator
{mFactories=??? mInstances=[...]() mMetaDataList=??? ...}


// mouse over Ogre::Root
{mRenderers=[...]() mActiveRenderer=??? mVersion={...} ...}


// mouse over Ogre::Root
{mRenderers=[...]() mActiveRenderer=??? mVersion={...} ...}

so the iter object is not created.

What am I doing wrong?

I put MyGUI initialisation after the Ogre Root init. and SceneManager init.

Have you checked initialization of RenderWindow? Does program create valid render window without MyGUI?

I put MyGUI initialisation after the Ogre Root init. and SceneManager init.

Have you checked initialization of RenderWindow? Does program create valid render window without MyGUI?

Yes, I tried to initialise CEGUI instead of MyGUI and it worked. So I don't see it in RenderWindow. Mabye...