Managed to "fix" it myself.
However, I had to install openbox 3.6.0 first (yet marked unstable) and the new dependencies (since lxappearance-obconf 0.2.2.3) libobrender31 and libobt4.
Works now, but should not be closed, as openbox 3.6.0 is still a little "futuristic" ;)
SUCCESS!
Managed to "fix" it myself.
However, I had to install openbox 3.6.0 first (yet marked unstable) and the new dependencies (since lxappearance-obconf 0.2.2.3) libobrender31 and libobt4.
Works now, but should not be closed, as openbox 3.6.0 is still a little "futuristic" ;)