WoWInterface - Need help with WorldMapDataProvider

Hi, I am trying to extend my AddOn with Icons on the Zone Maps, but... when I last did this Kind of stuff (around BC times), the WorldMap was a simple Frame like any other and Nothing with data Providers and all this.
So I tried to figure it out but it doesn't Show me any Icon.
Can anyone push me the Right way?

Here is the sample code I wrote to understand how all this works:

WorldmapSample.xml:

Code:

<Ui xmlns="http://www.blizzard.com/wow/ui/">

        <Script file="WorldmapSample.lua"/>



        <Frame name="WorldmapSamplePinTemplate" hidden="false" enableMouse="true" mixin="WorldmapSamplePinMixin" virtual="true">

                <Size x="12" y="12"/>

                <Layers><Layer level="OVERLAY"><Texture parentKey="texture" setAllPoints="true"></Texture></Layer></Layers>

        </Frame>

</Ui>

WorldmapSample.lua:

Code:

local Me=CreateFrame("Frame","WorldmapSampleFrame")

local pins={}

Me.WorldMapDataProvider = CreateFromMixins(MapCanvasDataProviderMixin)

WorldmapSamplePinMixin = CreateFromMixins(MapCanvasPinMixin)

WorldMapFrame:AddDataProvider(Me.WorldMapDataProvider)

print("WorldmapSample loaded")



-- WORLDMAP REMOVE DATA

function Me.WorldMapDataProvider:RemoveAllData()

        self:GetMap():RemoveAllPinsByTemplate("WorldmapSamplePinTemplate")

        wipe(pins)

        print("wiped pins")

end



-- WORLDMAP REFRESH DATA

function Me.WorldMapDataProvider:RefreshAllData()

        self:RemoveAllData()

        local mapid = self:GetMap():GetMapID()

        if mapid then 

                local pin=self:GetMap():AcquirePin("WorldmapSamplePinTemplate", mapid, 50,50)

                table.insert(pins, pin)                

        end

end



-- WORLDMAP PIN MIXIN : ON LOAD

function WorldmapSamplePinMixin:OnLoad()

        self:UseFrameLevelType("PIN_FRAME_LEVEL_AREA_POI")

        self:SetScalingLimits(1, 1.0, 1.2)

end



-- WORLDMAP PIN MIXIN : ON ACQUIRED

function WorldmapSamplePinMixin:OnAcquired(mapid, x,y)

        self:SetPosition(x, y)

        self:SetBackdrop(nil)

        self.texture:SetTexture("Interface/AddOns/WorldmapSample/unknown.tga")

        self:SetSize(12,12)

        self.texture:SetTexCoord(0, 1, 0, 1)

        self.texture:SetVertexColor(1, 1, 1, 1)        

        self:EnableMouse(true)

        self:Show()

        print("added pin at "..x.."/"..y.." to map "..mapid)

end



-- WORLDMAP PIN MIXIN : ON MOUSE EVENTS

function WorldmapSamplePinMixin:OnMouseEnter() print("Mouse Enter") end

function WorldmapSamplePinMixin:OnMouseLeave() print("Mouse Leave") end

function WorldmapSamplePinMixin:OnClick(button) print("Mouse Click") end

In Addition there is of Course a file "unknown.tga" in the WordmapSample Directory.

What happens is: I see the debug message telling me "added pin at 50/50 to map <id>"
So the OnAcquired function gets called. But I don't see the Icon on the Zone map.
Can anyone tell me what I'm doing wrong?