I created a custom page layout with SharePoint Designer for use as a new default or welcome page in a publishing site. The page layout should contain a summary link web part that is pre configured with a list of links. SharePoint Designer already has some sample links included in the webpart and I modified them as needed. The preview also in SharePoint Designer shows just what I need. But when I create a new page, using my custom page layout, in my SharePoint site, it has the summary link web part but empty without the links.
<PublishingWebControls:SummaryLinkWebPart runat="server" Description="Externe Datenquellen"
ListDisplayName="" HelpLink="" AllowRemove="True" IsVisible="True" AllowHide="True" UseSQLDataSourcePaging="True" SummaryLinkStore=""
ExportControlledProperties="True" DataSourceID="" Title="Externe Datenquellen" ViewFlag="0" NoDefaultStyle="" AllowConnect="True" FrameState="Normal"
PageSize="-1" AsyncRefresh="False" ExportMode="All" PartOrder="2" DetailLink="" ShowWithSampleData="False" ListId="00000000-0000-0000-0000-000000000000"
FrameType="TitleBarOnly" PartImageSmall="" PartImageLarge="" IsIncluded="True" SuppressWebPartChrome="False" AllowEdit="True" ManualRefresh="False" ChromeType="TitleOnly"
AutoRefresh="False" AutoRefreshInterval="60" AllowMinimize="True" ViewContentTypeId="" Dir="Default" InitialAsyncDataFetch="False" MissingAssembly="Cannot import this Web Part."
HelpMode="Modeless" ListUrl="" ID="g_9ff5513e_80b2_4c71_92c3_49c7db485df8" ConnectionID="00000000-0000-0000-0000-000000000000" AllowZoneChange="True" IsIncludedFilter=""
ZoneID="" __MarkupType="vsattributemarkup" __WebPartId="{9ff5513e-80b2-4c71-92c3-49c7db485df8}" WebPart="true" Height="" Width="">
<DataFields>
</DataFields>
<SampleData>
<dsQueryResponse>
<Rows>
<Row Title="Item1" LinkUrl="http://Item1" Order="2" BeginColumn="False" IsGroupHeader="False" />
<Row Title="Item2" LinkUrl="http://Item2" Order="3" BeginColumn="False" IsGroupHeader="False" />
<Row Title="Item3" LinkUrl="http://Item3" Order="4" BeginColumn="False" IsGroupHeader="False" />
<Row Title="Item4" LinkUrl="http://Item2" Order="3" BeginColumn="False" IsGroupHeader="False" />
<Row Title="Item5" LinkUrl="http://Item2" Order="3" BeginColumn="False" IsGroupHeader="False" />
<Row Title="Item6" LinkUrl="http://Item2" Order="3" BeginColumn="False" IsGroupHeader="False" />
</Rows>
</dsQueryResponse>
</SampleData>
<Xsl>
<xsl:stylesheet xmlns:x="http://www.w3.org/2001/XMLSchema" version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
xmlns:cmswrt="http://schemas.microsoft.com/WebPart/v3/Publishing/runtime" exclude-result-prefixes="xsl cmswrt x" >
<xsl:import href="/Style Library/XSL Style Sheets/Header.xsl" />
<xsl:import href="/Style Library/XSL Style Sheets/ItemStyle.xsl" />
<xsl:import href="/Style Library/XSL Style Sheets/SummaryLinkMain.xsl" />
</xsl:stylesheet>
</Xsl>