Refresh a control on the master page after postback

What i am trying to do here is to show a couple of validation messages in form of a bulletlist, so i have a Div on my master page containing a asp:bulletlist. Like this:

                <div>
                <asp:BulletedList ID="blstValidationErrorMessage" runat="server" BulletStyle="Disc">
                </asp:BulletedList>
            </div>

When i then click the Save button from any of my pages (inside the main contentPlaceHolder) i create a list of messages and give this list as datasouce like this:

                blstValidationErrorMessage.DataSource = validationMessageCollection;
                blstValidationErrorMessage.DataBind();   

The save button is located inside an updatepanel:

asp:UpdatePanel runat="server" ID="UpdatePanel" ChildrenAsTriggers="true" UpdateMode="Conditional">

Nothing happens, i can see that the datasource of the bulletlist contains X items, the problems must arise because the Save button is inside an update panel and the elements outside this updatepanel (master page controls for example) is not refreshed.

So my question is, how do i make the bulletlist refresh after the postback?

Thanks in advance.