On this forum I posted the following problem. Nobody had an answer, so I had to think about myself.
After rendering to DIB-Section all textures are lost !?
You have to reload all the textures for each rendering-context, even if you use the same display-list.
This is because texture-binding (with glBindTexture) in OpenGL is local for each rendering-context.
The documentation says: ‘Texture names and the corresponding texture contents are local to the shared display-list space of the current OpenGL rendering context; two rendering contexts share texture names only if they also share display lists.’
The last statement seems not to be true.
Maybe it helps someone.