Mesh Release() Problem

[Morgul]

I come from one problem onto the next one very quickly it seems.

I have never had a problem like this one before, and I don't think the reason is as stupid as the last one (though I could definitely be wrong).

Anyways, when I try to release stored mesh data in my program I am given an unhandled exception (again). The debugger tells me it roots back to IUnknown, specifically I get this error:

__vfptr CXX0030: Error: expression cannot be evaluated

Here is the code for the class where the destructor is being called in which this error is generated:

class MeshContainer {
private:
	vector<Mesh *> MeshList;
public:
	MeshContainer() {}
	~MeshContainer() {
		if(MeshList.size() > 0) {
			for(DWORD i=0; i<MeshList.size(); i++) {
				if(MeshList[i]->MeshData != NULL) {
					MeshList[i]->MeshData->Release();
					MeshList[i]->MeshData = NULL;
				}
				delete MeshList[i];
			}
			MeshList.clear();
		}
	}
	int DrawMesh(DWORD dwMeshID);
	int LoadMesh(IDirect3DDevice9* &g_pd3dDevice, int iMeshNum);
};

I am getting the error from the line:

MeshList[i]->MeshData->Release();

When I reach there, the program crashes.

Here is the mesh structure for reference:

struct Mesh {
	DWORD dwID;
	DWORD dwNumSubsets;
	ID3DXMesh* MeshData;
	Mesh() {
		dwID = 0;
		dwNumSubsets = 0;
		MeshData = NULL;
	}
};

And since I don't want to give to little like last time...
Here is the wrapper class which the MeshContainer class is used in:

class ResourceCache {
private:
	friend class CObjectManager;
	MaterialContainer *Materials;
	TextureContainer *Textures;
	MeshContainer *Meshes;
public:
	ResourceCache() {
		Materials = new MaterialContainer();
		Textures = new TextureContainer();
		Meshes = new MeshContainer();
	}
	~ResourceCache() {
		delete Materials;
		delete Textures;
		delete Meshes;
	}
	int DrawMesh(DWORD dwMeshID) {
		return Meshes->DrawMesh(dwMeshID);
	}
	int CreateMesh(LPDIRECT3DDEVICE9 &g_pd3dDevice, int iMeshNum) { return Meshes->LoadMesh(g_pd3dDevice, iMeshNum); }
};

Here is the initialization of that wrapper class elsewhere:

ResourceCache*							ResourceList = new ResourceCache();

And finally, here is the deletion statement for that wrapper class object:

delete ResourceList;

Here is the function in which I create the mesh data:

int MeshContainer::LoadMesh(IDirect3DDevice9* &g_pd3dDevice, int iMeshNum) {
	Mesh *TempMesh = new Mesh();
	switch(iMeshNum) {
		case MESH_TEAPOT: // Create a Teapot
			if(FAILED(D3DXCreateTeapot(g_pd3dDevice, &TempMesh->MeshData, 0)))
				return false;
			TempMesh->dwNumSubsets = 0;
			TempMesh->dwID = 0;
			break;
		default:
			return false;
			break;
	}
	MeshList.push_back(TempMesh);
	return true;
}

I am using MSVC++ 2005 EE (still). I'm not sure what the best way to explain the problem is. All I know is, I can't access the MeshData->Release() function successfully. This is a pain and it shouldn't be. I'm stumped (again). If something needs further clarification, just ask and I'll try to explain better.

Thanks in advance... .