I just ran in to this texture problem as well ... Images are not the only problem, fonts seem to have the same problem ... loading ttf files puts them upside down it seems the whole of sfml follows left-top as standard ... witch is fun ... I like to confuse people so
Good thing that I don't need collision detection on text ...
glRotatef(180.0, 1.0, 0.0, 0.0); // Silly sfml font ... flip it up side down
any way a bump, giving people a option to flip textures and fonts around would be appreciated. one vote for sf::Image::flip() and sf::Font::flip()
and euh I have no clue about standards but the way I learned it for opengl has always been bottom-left.