Wrong unused import for implicit conversion

Using IDEA 10 with Scala 0.4.345, it tells that import is unused in the following code:

class Vect(val x: Double, val y: Double)


class Coef(val d: Double) {
  def *(v: Vect) = new Vect(d * v.x, d * v.y)
}


object Coef {
  implicit def doubleToCoef(d: Double) = new Coef(d)
}


object Test extends Application {
  import Coef.doubleToCoef
  val v1 = new Vect(1, 0)
  val v2 = 2 * v1
}