yeah, i tried both 168 and 187, and yes, I'm using the full 5 digits. Looks like there might be no working sleep code for this model, which kind of sucks, and seems to be a design flaw on Samsung's part. In an attempt to make their new remotes more fancy and minimal, they have introduced complex sequences of menus and button-pushes. Something like "sleep", is something i want to do in one button push while drowsy and not in the mood to pay attention to a maze of menus. I just found a thread where others are complaining about this (see link below). If by chance anybody from Samsung is paying attention, it would be great to see a software update that changes this.
[Link: cnet.com]