RoundedCornersExtender Panel border (right-hand side) disappears when PopupControlExtender

Good Morning,

Trying to solve an annoying problem with the rounded corners extender from ajax control kit for the asp.net 20.0 framework.

When I click on textboxtxt6 (see below), the popup control extender causes txt6_details to appear, but when clicked on, the right-hand side border of theRoundedCornersExtender disappears (top, bottom and left-hand sides of border remain). Has anyone come across this problem before?

Thanks,
webconsult

<cc2:RoundedCornersExtenderID="RoundedCornersExtender1"TargetControlID="Panel1"Radius="10"Corners="All"runat="server"BorderColor="#8f8f8f"/>
<asp:Panelrunat="server"ID="Panel1">
<asp:tablerunat="server"width="100%"border="0"cellspacing="12"id="Table1">
.
.
<asp:UpdatePanelrunat="server"UpdateMode="Conditional"ID="UpdatePanel2">
<ContentTemplate>
<asp:UpdateProgressID="UpdateProgress1"runat="server"AssociatedUpdatePanelID="UpdatePanel2">
<ProgressTemplate>
<tableborder=0><tr><td><imgsrc="images/ajax-loader.gif"alt=""/></td><td><asp:LabelID="Label10"CssClass="bodytext"runat="server"Text="Saving details..."ForeColor="#1C7BB5"></asp:Label></td></tr><tr><tdcolspan="2"> </td></tr></table>
</ProgressTemplate>
</asp:UpdateProgress>
<asp:TextBoxID="txt6"runat="server"></asp:TextBox>
<cc2:PopupControlExtenderID="PopupControlExtender1"TargetControlID="txt6"PopupControlID="txt6_details"OffsetY="25"runat="server">
</cc2:PopupControlExtender>
<cc2:FilteredTextBoxExtenderID="FilteredTextBoxExtender1"runat="server"
TargetControlID="txt6"
FilterType="Custom, Numbers"
ValidChars="-."/>
<asp:TextBoxID="txt6_details"runat="server"CssClass="popupclass"Width="300"OnTextChanged="txt6_details_TextChanged"
MaxLength="500"Rows="5"TextMode="MultiLine"AutoPostBack="true"></asp:TextBox>
<cc2:TextBoxWatermarkExtenderID="TextBoxWatermarkExtender1"runat="server"TargetControlID="txt6_details"WatermarkText="If entering a figure please provide an explanation here..."WatermarkCssClass="watermarkclass">
</cc2:TextBoxWatermarkExtender>
</ContentTemplate>
<Triggers>
<asp:AsyncPostBackTriggerControlID="txt6_details"EventName="TextChanged"/>
</Triggers>
</asp:UpdatePanel>
.
.
</asp:table>
</asp:panel

For some reason, changing the txt6_details textbox width to 200 seemed to have fixed the problem.