I seem to recall someone mentioning a problem using the -1 parameters for setspritesize().
If this proves the case, an alternative would be using the values from the image itself, either using the same variable which assigned the image;
setSpriteImage( spr , myImage )
setSpriteSize( spr , getImageWidth( myImage ) , getImageheight( myImage ) )
or (if the image was assigned some other way such as by a function ) by pulling the image reference from the sprite itself;
setSpriteImage( spr , ImageAssignFunction() )
setSpriteSize( spr , getImageWidth( GetSpriteImageID( spr ) ) , getImageheight( GetSpriteImageID( spr ) ) )
Its always good to have a plan B