Twitter feed returns empty data but was working previously.

I use MS VWD 2010 Express(version 3.5) and Visual basic to develop a website for my rugby club. 

I set up an Ajax twitter control linked to our twitter account and this worked fine.

It has now just started to return the "empty data template" even though there are a number of recent tweets

No changes have been made to either the website or the Twitter account.  Any suggestions as to why the tweets aren't showing?

The code for my control is shown below:

Thanks

John

         <asp:Twitter ID="Twitter1" runat="server" IncludeReplies="True"  Width="265px" Count="4"
             IncludeRetweets="True"  ScreenName="Tabard_RFC">
              <EmptyDataTemplate>
             There are no matching tweets.
           </EmptyDataTemplate>
<LayoutTemplate>
<div id="Div5" runat="server" class="ajax__twitter_header"><asp:Image ID="Image4" runat="server"
        ImageUrl="~/images/Tabard.jpg"></asp:Image>

<h4 id="H1" runat="server">Tabard Tweets</h4>
</div>
<ul id="Ul2" runat="server" class="ajax__twitter_itemlist" style="margin:0px;"><asp:PlaceHolder runat="server" ID="ItemPlaceholder"></asp:PlaceHolder>
</ul>

</LayoutTemplate>
         </asp:Twitter>