The password answer is not formatted correctly.
Syntax
MembershipCreateStatus InvalidAnswer
Requirements
Namespace: System.Web.Security
Assembly: System.Web (in System.Web.dll)
Assembly Versions: 2.0.0.0
Since: .NET 2.0
Assembly: System.Web (in System.Web.dll)
Assembly Versions: 2.0.0.0
Since: .NET 2.0