Create User Wizard problem

I am using the create user wizard to create users on my site. To the best of my knowlage there is no built in way to do regex on a username so I did the regex in the code behind page and redirected if there was a problem. Ever since then I am getting half created user accounts. Here is my ASP
<asp:CreateUserWizard ID="CreateUserWizard1" runat="server" CreateUserButtonStyle-CssClass="buttonStyle" EmailRegularExpression="^([0-9a-zA-Z]([-\.\w]*[0-9a-zA-Z])*@([0-9a-zA-Z][-\w]*[0-9a-zA-Z]\.)+[a-zA-Z]{2,9})$" EmailRegularExpressionErrorMessage="Email address must be formatted properly." > <WizardSteps> <asp:CreateUserWizardStep ID="CreateUserWizardStep1" runat="server"></asp:CreateUserWizardStep> <asp:CompleteWizardStep ID="CompleteWizardSte ...