Si, what are you using SetPosition for, exactly?
SetPosition is an internal method of the gadget, used to calculate the value of the gadget based on the x or y location of the slider itself, using the right or bottom of the slighter as 0 and then working from there, pixel by pixel. It's so named because it locks the slider to the nearest allowed value, hence setting its position. Might be a tad confusing, I admit. It isn't documented though.
If what you're wanting to do is set the slider, with a range from 50 to 150, to a value of 103, then use gadget.SetValue(103).
SetPosition is an internal method of the gadget, used to calculate the value of the gadget based on the x or y location of the slider itself, using the right or bottom of the slighter as 0 and then working from there, pixel by pixel. It's so named because it locks the slider to the nearest allowed value, hence setting its position. Might be a tad confusing, I admit. It isn't documented though.
If what you're wanting to do is set the slider, with a range from 50 to 150, to a value of 103, then use gadget.SetValue(103).