Thanks Roeland :
If you are hopeless at programming, that's not a problem. You still don't need to write scripts to render something in Octane.
Good news!
What do you mean by the Daylight system doesn't work? Does it not render correctly or are there some inputs which don't work? Or do you get a GPU crash? I tested the daylight and texture environments with spherical mapping and didn't see any issues.
When selecting the daylight system, the render still displays the default grey background like the basic texture environment. I stopped and started again the render, switched from daylight to texture and back to daylight... nothing, no procedural sky and sun (tried old and new sky system).
I tried with creating a new scene in 1.25 as well as opening ocs made with 1.20a ... with same result : no procedural sky and sun.
In 1.20a it works perfectly.

EDIT :
I have deleted the default Environment node and created a new one from scratch, and the Daylight system now works fine !
By the way : negative scaling is still not available in transform ?

French Blender user - CPU : intel Quad QX9650 at 3GHz - 8GB of RAM - Windows 7 Pro 64 bits. Display GPU : GeForce GTX 480 (2 Samsung 2443BW-1920x1600 monitors). External GPUs : two EVGA GTX 580 3GB in a Cubix GPU-Xpander Pro 2. NVidia Driver : 368.22.