Comment 2 for bug 754399

snippet from default preferences:

  <group
     id="iconpreview"
     autoRefresh="1"
     pack="1"
     selectionHold="1"
     showFrames="1"
     selectionOnly="0">
    <group
       id="sizes">
      <group
         id="default">
        <group
           value="16"
           show="1"
           id="size16" />
        <group
           value="22"
           show="0"
           id="size22" />
        <group
           value="24"
           show="1"
           id="size24" />
        <group
           value="32"
           show="1"
           id="size32" />
        <group
           value="48"
           show="1"
           id="size48" />
        <group
           value="50"
           show="0"
           id="size50" />
        <group
           value="64"
           show="0"
           id="size64" />
        <group
           value="72"
           show="0"
           id="size72" />
        <group
           value="80"
           show="0"
           id="size80" />
        <group
           value="96"
           show="0"
           id="size96" />
        <group
           value="128"
           show="1"
           id="size128" />
        <group
           value="256"
           show="0"
           id="size256" />
      </group>
    </group>
  </group>