Render Bug with more than one object

[SuperManitu]

Hello,
I'm currently programming a little 2D-Engine only for make 2D-Development shorter.
But I've got a problem with Rendering. I have got a class defining an entity, which has a render() method. In this method a simple quad is drawn with glBegin ang glEnd. The problem i get is, when I try to add a second object of this class the second one has no texture, it's only black. It can't be an error ar loading the picture, because when i activate alpha test, the black object have the right shape (the first object is rendered normal).
Does anyone have an idea? Thanks.