SDL_FreeSurface and segfault

Hello,

I I have a verry bad problem.

In my draw.h :

[source lang="cpp"]class CDraw : public CGraphic
{

public :

// constructor
CDraw(const float& coef_resol_);

...

private :
SDL_Surface *destimg;
}[/source]

In my draw.cpp :

[source lang="cpp"]CDraw::CDraw(const float& coef_resol_) : CGraphic({0, 0}, coef_resol_), texture(NULL), destimg(NULL) {
}

void CDraw::~CDraw() {
if(surface)
SDL_FreeSurface(surface);

/* segfault with it :-( */
if(destimg)
SDL_FreeSurface(destimg);
}
[/source]

Well in all lines in draw.cpp, i'm not working with destimg. i commented all destimg. I have only destimg(NULL) and if(destimg) SDL_FreeSurface(destimg);

With gdb, with a break point before the if(destimg) i have :

(gdb) print destimg
$2 = (SDL_Surface *) 0x766177

And next a SEGFAULT.

I don t understand, thanks