Undefined reference to vtable

Hi, I'm having an odd linker error that I don't know how to solve. It is telling me that there is an undefined reference to the vtable for EndState() and ~EndState() constructor and destructor. I've looked around the web and it seems this kind of error is related to classes inheriting from pure virtual classes (EnState inherits from GameState, which is pure virtual).
Here's my project files (includes VS10 and PN projects):
> [www.mediafire.com]

Does anyone know how I can fix this?

EDIT:
EndState header: include\game_state\end_state.h
EndState source: source\game_state\end_state.cpp

GameState abstract class header: include\game_state\game_state.h
GameState abstract class source: (no source)



Edited 4 time(s). Last edit at 05/09/2010 12:47PM by diego_pmc.

In end_state.cpp,

change:

void onOpen() {}
void onClose() {}

to:

void EndState::onOpen() {}
void EndState::onClose() {}

See if that makes any difference.

Michael

That solved it, thanks a million. (Silly mistake.)