I would like for my LinkButton to submit my login request upon hitting Enter.

This is my LinkButton(note: resides in a LoginView[Anonymous] template):

Code:
<asp:Panel ID="Panel1" runat="server" DefaultButton="loginButton">
<asp:LinkButton  ID="loginButton" CssClass="btnLogin" CommandName="Login" 
CausesValidation="true" ValidationGroup="Login1" runat="server" UseSubmitBehavior="false" Text="Sign In" />
</asp:Panel>
IE is ok.
Firefox bad.

I've come across some fixes that seem very convoluted and unnecessary.
Can someone please provide me with an easy fix?