does "edgemain.h" interface contain IMPLEMENTATION

if i try to include the header "edgemain.h" in two different and independent (no inheritance relation) clases (defined in separate files), it displays error.
i had 2 classes:
____________________________________
#include "edgemain.h"
class ModuleManager
{
//using ClassEDsiplay, etc
}
____________________________________
#include "edgemain.h"
class TiledImage
{
//using E2DSurface . . .etc
}
____________________________________
in this case it displays the error:
dupllicate symbol: ERender_Get_GetBltFast8 . . .
. . . g++-4.0 failed with exit code 1
i had 2 classes:
____________________________________
#include "edgemain.h"
class ModuleManager
{
//using ClassEDsiplay, etc
}
____________________________________
#include "edgemain.h"
class TiledImage
{
//using E2DSurface . . .etc
}
____________________________________
in this case it displays the error:
dupllicate symbol: ERender_Get_GetBltFast8 . . .
. . . g++-4.0 failed with exit code 1