For a panel with one textbox and one button which is its default button, the DefaultButton event fires only once as editing textbox details again and pressing enter, event doesn't fire.

```
<asp:Panel runat="server" ID="pnlNewFolderDetails" DefaultButton="btnAddFolder">
     <asp:Label runat="server" ID="lblFolderHeader" Text="New Folder Name" CssClass="label" />
     <asp:TextBox runat="server" ID="txtFolderName" ToolTip="Folder Name" />
<asp:Button runat="server" ID="btnAddFolder" OnClick="btnAddFolder_Click" Text="Add" />

```

Any suggestions?