Unexpected Full Transparent GUI

[ichigo325 0]

;Right-click/ESC to exit
;Playing with AutoIt GUI

$mGui = GUICreate("Full Transparent GUI", 300, 300, -1, -1, 0x80000000)
GUISetBkColor(0xffffff, $mGui)
WinSetTrans($mGui, "", 160) 
GUICtrlCreatePic("", 0, 0, 181, 101, -1) ;test code

GUICtrlCreateLabel("wololo~", 5, 6, 300, 100,-1,0x00080000)
GUICtrlSetFont(-1, 48, 600, -1, "Lucida Handwriting", "CLEARTYPE_QUALITY=5")
GUICtrlSetBkColor(-1, -2)

GUICtrlCreateProgress(10, 80, 280, 20,-1)
GUICtrlSetData(-1,99.9)
GUICtrlSetState(-1,256)

GUICtrlCreateEdit(FileRead(FileOpen(@ScriptFullPath,0)),10,110,280,100,-1,0x00100000)
GUICtrlSetBkColor(-1,0xfffffe)

GUISetState()

While 1
    $Msg2 = GUIGetMsg()
    If $Msg2 = -9 Then Exit
WEnd

Can someone tell me why the GUI fully transparent after i added "GuiCtrlCreatePic"?