The issue: ProfileGroupBase implementations in a Web Application vs. a Web Site.

The Solution: Special instance overrides using the “new” keyword on certain methods in conjunction with leaving the “group” element definitions in the web.config file.

As an example; I’ve created a UserProfile object deriving from ProfileBase, a UserProfileAddress object deriving from ProfileGroupBase and a UserProfileShippingAddress deriving from UserProfile Address. The class code in show below.

[Serializable]
public class UserProfile : ProfileBase
{
	/// <summary>The user's first name.</summary>
	public string FirstName { get { return GetPropertyValue("FirstName").ToString(); } set { SetPropertyValue("FirstName", value); } }


	/// <summary>The user's last name.</summary>
	public string LastName { get { return GetPropertyValue("LastName").ToString(); } set { SetPropertyValue("LastName", value); } }


	/// <summary>The user's email address.</summary>
	public string EmailAddress { get { return GetPropertyValue("EmailAddress").ToString(); } set { SetPropertyValue("EmailAddress", value); } }


	/// <summary>The user's day time phone number.</summary>
	public string DayTimePhone { get { return GetPropertyValue("DayTimePhone").ToString(); } set { SetPropertyValue("DayTimePhone", value); } }


	/// <summary>Gets or sets the billing address.</summary>
	public UserProfileAddress BillingAddress { get { return GetProfileGroupSpecial<UserProfileAddress>("BillingAddress"); } }


	/// <summary>Gets or sets the shipping address.</summary>
	public UserProfileShippingAddress ShippingAddress { get { return GetProfileGroupSpecial<UserProfileShippingAddress>("ShippingAddress"); } }


	/// <summary>Get a special mapped instance of the profile group.</summary>
	/// <typeparam name="T">The type of group.</typeparam>
	/// <param name="name">The group name.</param>
	/// <returns>An instance of the special mapped group.</returns>
	private T GetProfileGroupSpecial<T>(string name) where T : UserProfileAddress, new()
	{
		T retVal = default(T);
		try
		{
			retVal = new T();
			retVal.Init(this, name);
		}
		catch { /* Not much we can do here, logging? */ }
		return retVal;
	}


	/// <summary>Get the profile of the currently logged-on user.</summary>
	public static UserProfile GetProfile()
	{
		return (UserProfile)HttpContext.Current.Profile;
	}


	/// <summary>The current user's profile.</summary>
	public static UserProfile Current { get { return (UserProfile)HttpContext.Current.Profile; } }


	/// <summary>Gets the profile of a specific user.</summary>
	/// <param name="userName">The user name of the user whose profile you want to retrieve.</param>
	public static UserProfile GetProfile(string userName)
	{
		ProfileBase profile = Create(userName);
		return (UserProfile)profile;
	}
}
[Serializable]
public class UserProfileAddress : ProfileGroupBase
{
	/// <summary>Private reference to name.</summary>
	private string _myName = null;


	/// <summary>Private reference to parent.</summary>
	private ProfileBase _parent = null;


	/// <summary>Called by the parent when creating.</summary>
	/// <param name="parent">The parent.</param>
	/// <param name="myName">The group name.</param>
	/// <remarks>Intentionally hides inherited member.</remarks>
	new public void Init(ProfileBase parent, string myName)
	{
		if (_parent == null)
		{
			_parent = parent;
			_myName = myName + ".";
		}
	}


	/// <summary>Address line 1.</summary>
	public string Line1 { get { return GetPropertyValue("Line1").ToString(); } set { SetPropertyValue("Line1", value); } }


	/// <summary>Address line 2</summary>
	public string Line2 { get { return GetPropertyValue("Line2").ToString(); } set { SetPropertyValue("Line2", value); } }


	/// <summary>City name</summary>
	public string City { get { return GetPropertyValue("City").ToString(); } set { SetPropertyValue("City", value); } }


	/// <summary>State ID</summary>
	public int State { get { return Convert.ToInt32(GetPropertyValue("State")); } set { SetPropertyValue("State", value); } }


	/// <summary>postal code</summary>
	public string Zip { get { return GetPropertyValue("Zip").ToString(); } set { SetPropertyValue("Zip", value); } }


	/// <summary>Country ID</summary>
	public int Country { get { return Convert.ToInt32(GetPropertyValue("Country")); } set { SetPropertyValue("Country", value); } }


	/// <summary>Gets the value of a named property.</summary>
	/// <param name="propertyName">The property name.</param>
	/// <returns>The value of the named property.</returns>
	/// <remarks>Intentionally hides inherited member.</remarks>
	new public object GetPropertyValue(string propertyName)
	{
		return this._parent[this._myName + propertyName];
	}


	/// <summary>Sets the value of a named property.</summary>
	/// <param name="propertyName">The name of the property.</param>
	/// <param name="propertyValue">The value to set.</param>
	/// <remarks>Intentionally hides inherited member.</remarks>
	new public void SetPropertyValue(string propertyName, object propertyValue)
	{
		this._parent[this._myName + propertyName] = propertyValue;
	}


	/// <summary>Gets or set the value of a named property.</summary>
	/// <param name="propertyName">The property name.</param>
	/// <returns>The value of the named property.</returns>
	/// <remarks>Intentionally hides inherited member.</remarks>
	new public object this[string propertyName]
	{
		get
		{
			return this._parent[this._myName + propertyName];
		}
		set
		{
			this._parent[this._myName + propertyName] = value;
		}
	}
}
[Serializable]
public class UserProfileShippingAddress : UserProfileAddress
{
	/// <summary>The recipients first name.</summary>
	public string FirstName { get { return GetPropertyValue("FirstName").ToString(); } set { SetPropertyValue("FirstName", value); } }


	/// <summary>The recipients last name.</summary>
	public string LastName { get { return GetPropertyValue("LastName").ToString(); } set { SetPropertyValue("LastName", value); } }
}

The web config is relatively straigt forward but ONLY includes definitions for groups. Including anything else will cause duplicate definition exceptions.

<profile defaultProvider="MyProfileProvider" automaticSaveEnabled="false" inherits=" UserProfile">
	<providers>
		<clear/>
		<add name="MyProfileProvider" type="System.Web.Profile.SqlProfileProvider" connectionStringName="MyConnectionString" applicationName="MyApp"/>
	</providers>
	<properties>
		<group name="BillingAddress">
			<add name="Line1" type="System.String" allowAnonymous="true"/>
			<add name="Line2" type="System.String" allowAnonymous="true"/>
			<add name="City" type="System.String" allowAnonymous="true"/>
			<add name="State" type="System.Int32" allowAnonymous="true"/>
			<add name="Zip" type="System.String" allowAnonymous="true"/>
			<add name="Country" type="System.Int32" allowAnonymous="true"/>
		</group>
		<group name="ShippingAddress">
			<add name="FirstName" type="System.String" allowAnonymous="true"/>
			<add name="LastName" type="System.String" allowAnonymous="true"/>
			<add name="Line1" type="System.String" allowAnonymous="true"/>
			<add name="Line2" type="System.String" allowAnonymous="true"/>
			<add name="City" type="System.String" allowAnonymous="true"/>
			<add name="State" type="System.Int32" allowAnonymous="true"/>
			<add name="Zip" type="System.String" allowAnonymous="true"/>
			<add name="Country" type="System.Int32" allowAnonymous="true"/>
		</group>
	</properties>
</profile>