Frame not sizing or positioning when told to by script?!

So, I have this function and it creates a frame onto an existing one. The existing frame is registered and all that good stuff, but when I try to resize and reposition the new frame with the existing frames size and position it doesn't work. No errors, just a frame that is at {0,0,0,0} size and {0,0,0,0} position. Here is the code:

function createWhite(lastFrame)
	local frameToGet = Bars:FindFirstChild(tostring(lastFrame))
	local frame = Instance.new("Frame", script.Parent.ImageLabel["Bar Frames"])
	frame.Visible = true
	frame.Name = "ShootingFrame"
	frame.BackgroundColor3 = Color3.new(255/255,255/255,255/255) --// White
	frame:TweenSize(UDim2.new(frameToGet.Size))
	frame:TweenPosition(UDim2.new(frameToGet.Position))
	frame.Rotation = frameToGet.Rotation
	frame.ZIndex = 3
	lastSpotVal = frameToGet.SpotValue.Value
end