Solved temporarily by adding:    <style>        
        /* The missing scrollbar in RadListBox is due to a bug in IE and Firefox and it is related to using a FooterTemplate/HeaderTemplate. */
        html .RadListBox.rlbFixedHeight .rlbTemplate .rlbTemplateContent,
        html .RadListBox.rlbFixedHeight .rlbTemplate .rlbBody,
        html .RadListBox.rlbFixedHeight .rlbTemplate .rlbHeader,
        html .RadListBox.rlbFixedHeight .rlbTemplate .rlbFooter {
            display: block;
        }

        html .RadListBox.rlbFixedHeight .rlbTemplate .rlbBody {
            height: 166px;
        }
    </style>

I cannot manage RadListBox to show vertical nor horizontal scrollbars.

<telerik:RadListBoxrunat="server"ID="lbIndicadoresSource"Height="150px"Width="600px"AllowTransferOnDoubleClick="true"ButtonSettings-VerticalAlign="Middle"SelectionMode="Multiple"AllowTransfer="true"TransferToID="lbIndicadoresDestination"meta:resourcekey="ListBoxSeleccionIndicadores"><HeaderTemplate><h5><asp:LabelID="Label1"runat="server"Text="Available indicators"meta:resourcekey="LabelIndicadoresDisponibles"></asp:Label></h5></HeaderTemplate></telerik:RadListBox><telerik:RadListBoxrunat="server"ID="lbIndicadoresDestination"Height="150px"Width="600px"AllowReorder="true"AllowTransferOnDoubleClick="true"ButtonSettings-VerticalAlign="Middle"SelectionMode="Multiple"OnClientLoad="OnClientLoadHandler"meta:resourcekey="ListBoxSeleccionIndicadores"><HeaderTemplate><h5><asp:LabelID="Label2"runat="server"Text="Selected indicators"meta:resourcekey="LabelIndicadoresSeleccionados"></asp:Label></h5></HeaderTemplate></telerik:RadListBox>

Hello, I had the same problem as descripted by Kjell in this report:
http://www.telerik.com/forums/scrollbar-98d2c06f1d59

The scrollbar of radlistbox disappears when using <HeaderTemplate> on IE.9. 

The provided workaround seems to be working on IE, Firefox and Chrome even if I get a non-critical JS exception on IE.9 as you can see in "JsException_RadListBox_Workaround_IE9.PNG".

Regards, 
Jade