I'm trying to use the MemberShipProvider exclusively to create new members. It is my understanding that the ProfileProvider has also been implemented in the latest versions of Umbraco, so this should not be very difficult.

I want to add extra fields to the registration page, for example: "Last name". 

The membership provider in my web.config is set to:

    <membership defaultProvider="UmbracoMembershipProvider" userIsOnlineTimeWindow="15">
      <providers>
        <clear />
        <add name="UmbracoMembershipProvider" type="umbraco.providers.members.UmbracoMembershipProvider" enablePasswordRetrieval="true" enablePasswordReset="true" requiresQuestionAndAnswer="false" defaultMemberTypeAlias="member" />
      </providers>
    </membership>

And I've added an extra section under that for the profile values:

    <profile enabled="true">
      <properties>
        <add name="lastname"/>
      </properties>
    </profile>

After reading this article, it sounds as if I can very easily save the profile information, the "create user" template looks like this:

<%@ Master Language="C#" MasterPageFile="/masterpages/Master.master" AutoEventWireup="true" %>

<script Langauge="C#" runat="server">
    protected void CreatedUser(Object sender, EventArgs e) 
    {
            /* User is created and setting extra parameters to profile */
        TextBox lastname= (TextBox)CreateUserWizard1.CreateUserStep.ContentTemplateContainer.FindControl("lastname");
            Profile.lastname = lastname.Text;
    }
</script>

<asp:content ContentPlaceHolderId="body" runat="server">
<form runat="server">
<asp:CreateUserWizard ID="CreateUserWizard1" OnCreatedUser="CreatedUser" runat="server">
    <WizardSteps>
        <asp:CreateUserWizardStep ID="CreateUserWizardStep1" runat="server">
        <ContentTemplate>     
            <asp:TextBox Runat="server" ID="lastname"></asp:TextBox><br />
            <asp:TextBox Runat="server" ID="username"></asp:TextBox><br />
            <asp:TextBox Runat="server" ID="password"></asp:TextBox><br />
            <asp:TextBox Runat="server" ID="email"></asp:TextBox><br />
        </ContentTemplate>
        </asp:CreateUserWizardStep>

        <asp:CompleteWizardStep ID="CompleteWizardStep1" runat="server">
        </asp:CompleteWizardStep>
    </WizardSteps>
</asp:CreateUserWizard>
</form>
</asp:content>

So as soon as the user has been created the Profile.lastname value should be set. 

I get a nice message saying that a new member has been created, but when I look in the backoffice, it has not saved the "lastname" property.
I checked the casing of the "lastname" alias on my member type properties, it is all lower case so that should not be a problem. Besides, I get no errors anywhere.

So... Who's tried using the profile provider and has succeeded? I know I can do it the manual way, but the whole point of the membership provider is that I shouldn't have to go through the umbraco API any more.