custom membership provider

I am trying to mock up a custom membership provider to our in house database. I've created the class, login page, etc... I am getting the following error: Could not load type 'iPMNMembershipProvider'.

It might be something to do with my folder structure, but I've been moving things around and can't figure it out.

So as a root level folder I have CustomMembershipProviderTest. In that folder I have an App_Code folder that contains my class iPMNMembershipProvider.vb.

At the root level of the site (same level as CustomMembershipProvider, not within that folder) I have a web.config file that contains the following:

Edit: Forgot to add the code from the beginning of my class file:
Public Class iPMNMembershipProvider
    Inherits MembershipProvider
    Private conn As String
    Public Overrides Sub Initialize(ByVal name As String, ByVal config As System.Collections.Specialized.NameValueCollection)

        conn = ConfigurationManager.ConnectionStrings("web_ipmnConnectionString").ConnectionString
        MyBase.Initialize(conn, config)

    End Sub

<membership defaultProvider="iPMNMembershipProvider">
			<providers>
				<add name="iPMNMembershipProvider" 
             type="iPMNMembershipProvider" 
             requiresQuestionAndAnswer="false" 
             enablePasswordRetrieval="true" 
             enablePasswordReset="true" 
             connectionStringName="web_ipmnConnectionString"/>
			</providers>
		</membership>
 
<add name="web_ipmnConnectionString" connectionString="Data Source=SQLSERVER; Initial Catalog=ipmn; User ID=xxx;pwd=xxxxxv; Integrated Security=True" providerName="System.Data.SqlClient"/>