Change webpart property value inside Site Definition

Hi, I have a webpart with a property "NbItemsReturned" that I want to change its value to "5" inside the Site Definition but it is not taking effect. Even when I launch the powershell that deletes the Site Collection and recreates it with the new solution, it always returns me "0" as "NbItemsReturned". Any help pls?

<Modules><Module Name="Portal" Url="$Resources:osrvcore,List_Pages_UrlName;" Path=""><File Url="default.aspx" Type="GhostableInLibrary" ><Property Name="Title" Value="$Resources:ABCD.Intranet.Portal,WelcomePage_Title;" /><Property Name="PublishingPageLayout" Value="~SiteCollection/_catalogs/masterpage/Layouts/Home.aspx, $Resources:ABCD.Intranet.Portal,PageLayout_Home_Title;" /><Property Name="ContentType" Value="$Resources:ABCD.Intranet.Portal,ContentType_WelcomePageABCD_Name;" /><AllUsersWebPart WebPartZoneID="Zone1" WebPartOrder="1"><![CDATA[<webParts>  <webPart xmlns="http://schemas.microsoft.com/WebPart/v3"> <metaData>      <type name="ABCD.Intranet.Portal.WebParts.ActualitesDuMinistereWP.ActualitesDuMinistereWP, ABCD.Intranet.Portal, Version=1.0.0.0, Culture=neutral, PublicKeyToken=abd81090242ea263" /><importErrorMessage>$Resources:cmscore,WebPartImportError;</importErrorMessage>    </metaData>  <data><properties><property name="Title" type="string">$Resources:ABCD.Intranet.Portal,WebPart_AlaUneMinisteres_DisplayName;</property><property name="Description" type="string">$Resources:ABCD.Intranet.Portal,WebPart_AlaUneMinisteres_Description;</property>                <property name="CacheTime" type="int">30</property><property name="UrlRss" type="string">http://rss.feedsportal.com/c/32788/f/524042/index.rss</property>
 HERE >>> <property name="NbItemsReturned" type="int">5</property> <<<<<<<<< HERE!!!!           <property name="ChromeType" type="chrometype">TitleOnly</property></properties></data></webPart></webParts>
          ]]></AllUsersWebPart>