Noob question on Validation Summary control

I think this problem is probably a simple solution.

Im trying to use Validation Summary control, when i run the page and enter invalid input i get the error summmary (fine) but when i try to rectify the error by entering correct info the page wont run and the summary stays (even though the Validation Control message goes.)

Thanks

<asp:RegularExpressionValidator ID="regexStns" runat="server" 
        ControlToValidate="txtStones" 
        ErrorMessage="Weight (Stns) Must be o开发者_如何学JAVAne or two number characters." 
        ValidationExpression="/d/d?"></asp:RegularExpressionValidator>
    <asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server" 
        ControlToValidate="txtPounds" ErrorMessage="RegularExpressionValidator" 
        ValidationExpression="\d\d?"></asp:RegularExpressionValidator>
    <br />
    <asp:ValidationSummary ID="ValidationSummary1" runat="server" />
    <br />

That is the normal behavior of the ValidationSummary control.