Problem with passing pointers ( touserdata )

[Michael Bauroth <Michael.Bauroth@...>]

Hi,

I'm using an ARM port of Lua (Lua5.1-CE). Don't know if this matters. 
Additionally I'm using Lunar / Luna to register a class and some 
functions to Lua, e.g.

const char FComponent::className[] = "Component";
FLuna< FComponent >::RegType FComponent::methods[] = {
    method( FComponent, SetPosition ),
    method( FComponent, SetDimensions ),
    method( FComponent, SetBackground ),
    method( FComponent, SetParent ),
    { 0, 0 }
};

Creating the object from Lua works well, e.g.

comp = Component:new()
print( comp )

result in Lua is: Button (000ADE70)
pointer in C++: 0x000ade70

Both sides (C++ and Lua) show the same pointer value.
When I use this value in the next step to send it back from Lua to C++, 
the value differs in C++ !?

comp = Component:new()
print( comp )
comp:SetParent( comp )

--> comp is 000ADE70

int FComponent::SetParent( lua_State *L )
{
    void* value = ( void*)lua_touserdata( L, 1 );
    return 0;
}

--> value is 0x000adf28


What happens here? Am I missing something?
Help / hints would be very appreciated.

Thanks in advance.
Micha