Using SDL_Image to display png images

Hi,
Recently I have been experimenting with SDL_Image implementation into my program, simply because bmps do not support transparency and are too memory intensive. The problem I am facing with it is that it doesn't display images other than bmp. I have linked in the SDL_image.lib and .h file into my program, I assume I have missed something out in my program, here is the code I use:
part of the Sprite loading/drawing class

SDL_Surface* SDL_Graphics::LoadImage(const char* ImageFileName)
 {
    SDL_Surface* Image = IMG_Load(ImageFileName);

    return Image;
 }

void SDL_Graphics::CloseImage(SDL_Surface* Image)
 {
    SDL_FreeSurface(Image);
 }

void SDL_Graphics::BeginScene()
 {
   // Clear the screen
    SDL_FillRect(m_screen, 
                 NULL, 
                 SDL_MapRGB(m_screen->format, m_BackgroundColorRed, 
                                              m_BackgroundColorGreen, 
                                              m_BackgroundColorBlue));
 }

// This just displays the scene.
void SDL_Graphics::EndScene()
 {
    SDL_Flip(m_screen);
 }

void SDL_Graphics::DrawSprite(SDL_Surface* imageSurface,
                              int srcX, int srcY, 
                              int dstX, int dstY,
                              int width, int height)

 {
    SDL_Rect srcRect;
    srcRect.x = srcX;
    srcRect.y = srcY;
    srcRect.w = width;
    srcRect.h = height;

    SDL_Rect dstRect;
    dstRect.x = dstX;
    dstRect.y = dstY;
    dstRect.w = width;
    dstRect.h = height;

    SDL_BlitSurface(imageSurface, &srcRect, m_screen, &dstRect);
 }

Further on, if required here is my menu class which inherits from the sprite loading/drawing class (I use the menu class in the main to display the images.)

Menu::Menu(SDL_Graphics* graphics,
		int imageX, int imageY,
        int width, int height,
        const char* ImageFileName,
        float x, float y) : m_graphics(graphics),
						  m_imageX(imageX), m_imageY(imageY),
						  m_width(width), m_height(height),
						  m_x(x), m_y(y)
{
	m_image = m_graphics->LoadImage(ImageFileName);
}

Menu::~Menu()
{
	m_graphics->CloseImage(m_image);
}


void Menu::draw()
{
	m_graphics->DrawSprite(m_image,
						   m_imageX, m_imageY,
						   m_x, m_y,
						   m_width, m_height);
}

Thanks in advance!