Odd behavior assigning Bitmaps to ImageView

Sub imgViewFlashMode_Click
   Dim flashSetting As String
   
   flashSetting = imgViewFlashMode.Tag
   
   Select flashSetting
      Case "1"
         imgViewFlashMode.Bitmap = LoadBitmap(File.DirAssets,"FlashOn.png")
         imgViewFlashMode.Tag = "2"
      Case "2"
         imgViewFlashMode.Bitmap = LoadBitmap(File.DirAssets,"FlashOff.png")
         imgViewFlashMode.Tag = "3"
      Case "3"
         imgViewFlashMode.Bitmap = LoadBitmap(File.DirAssets,"FlashAuto.png")
         imgViewFlashMode.Tag = "1"
   End Select
End Sub