Non-alphanumerical condition in user registration

Hi
I have reconfigured my webconfig as follow (to remove non-alphanumerical characters condition in user registration):
<add name="AspNetSqlMembershipProvider" type="System.Web.Security.SqlMembershipProvider" connectionStringName="ApplicationServices" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" requiresUniqueEmail="false" maxInvalidPasswordAttempts="5" minRequiredPasswordLength="6" minRequiredNonalphanumericCharacters="0" passwordAttemptWindow="10" applicationName="/" /> But when user want to register they forced to enter non-alphanumerical characters!
Any help would be appreciated.