Daniels118, this is a tricky one which already happened to me.
It's because you mixed the types of values in [font=courier new]SpinnerNumberModel[/font] instance: you gave [font=courier new]double[/font] values at its instantiation and then set the spinner value with a value of [font=courier new]float[/font] type. Casting the set value to [font=courier new]double[/font] or creating a [font=courier new]Double[/font] instance should fix it.