App.Config File Errors

Wjy is it that when I use this code in a class being accessed from an aspx page that the values don't get loaded from the config file but when I use it in a windows form it works?

Code:

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'Config file
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
        <appSettings>
                <add key="ConnectionString" value="Initial Catalog=Replica;Data Source=localhost;Integrated Security=SSPI;" />
                <add key="PathToTranscripts" value="F:\Transcripts Backup\ParsedFiles" />
        </appSettings>
</configuration>

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Code:

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'Class Code
Imports Word
Imports System
Imports System.IO
Imports System.Configuration
Imports System.Data.SqlClient
Imports Microsoft.ApplicationBlocks.Data

Namespace Transcripts
    Public Class Tools
        Dim conn As New SqlConnection
        Dim strPathToTranscripts As String   
        Dim ds As New DataSet

        Public Sub New()
            conn.ConnectionString = ConfigurationSettings.AppSettings("ConnectionString")
            strPathToTranscripts = ConfigurationSettings.AppSettings("PathToTranscripts")
        End Sub

'etc......

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