There's a problem with radSearchbox inserted in a radWindow contenttemplate.
On First show  then inputText width is equal to 0 until a contextitem is selected or a button pushed . (test on ie10 firefox and chrome)


code example :

  <telerik:RadWindow runat="server" ID="RadWindow1" Modal="true"     AutoSize="true"
        Behaviors="Close,Move">
        <ContentTemplate>
         <telerik:RadSearchBox ID="RadSearchBox1" runat="server" Width="350" SearchContext-ShowDefaultItem="False"
                        OnClientSearch="onClientSearch" OnClientButtonCommand="onClientButtonCommand"
                        ShowSearchButton="false" Skin="Default">
                       
                        <DropDownSettings Height="150" Width="300" />
                        <Localization LoadingItemsMessage="recherche en cours....." DefaultItemText="Saisissez le nom du point ici" />
                        <WebServiceSettings Path="PointDeTournee.aspx" Method="GetResults" />
                        <SearchContext>
                            <Items>
                                <telerik:SearchContextItem Text="POI" Key="1" ImageUrl="../Img/POI/Special_Divers-Bl.bmp"  Selected="true"/>
                                <telerik:SearchContextItem Text="PA" Key="2" ImageUrl="../Img/POI/PA.bmp" />
                            </Items>
                        </SearchContext>
                    </telerik:RadSearchBox>
          </ContentTemplate>
    </telerik:RadWindow>