Avoid gap between in textures while scaling in OpenGL ES 1.1

Question

I am using glScale() to zoom out whole game scene. But at some scales I get a gap between textures:

How can I avoid this gap?

I have already tried to put upper texture little lower. But then I get a darker line between textures (because my textures have alpha channel).

I may scale down whole scene manually in CPU (by calculating vertices for scaled textures). But in this case I can't take advantage of VBOs, because vertices will change in every frame (zooming is very dynamic in my case).

What you can suggest to avoid this gap between textures, when I scale down the scene?

Answer 1

I wasn't able to found a solution with textures. Thus, I have created one more texture big enough to contain two these texture I wanted to draw. I have rendered to these two texture to this additional texture (using FBO). And finally I render the scene using this big one texture.