llSetRot doesn't kick in until a multiple of 5deg

llSetRot doesn't seem to kick in, or perhaps the SL client doesn't update the screen visually until, it hits some multiple of 5degrees. So for example rotating somethin 1, 2, 3, or 4 degrees will not work, but 5 degrees will. 6, 7, 8, or 9 won't work but 10 degrees will, and so on.

So for example if you want to rotate something 2deg, you can't. however if you check the rotation on the object itself you find that it "thinks" it has rotated the 2deg you set. This leads me to suspect that perhaps it is being rotated, but for some reason the SL client is not being told to update itself.

i noticed the same thing.
it's the client not updating, for some reason.
i tested it by doing a small rotation, llSay()ing the before and after rotations -- according to the game engine, it did indeed move, though it hadn't moved on my screen.
then i teleported elsewhere and teleported back, and it was visually rotated to the correct new position.

I think the vehicle code must use llSetRot too, because I notice when you ride vehicles they seem to rotate in 5deg jumps too.