MS Project Plugin using VSTO - Need to Encrypt Config

[Antonio Santana]

I have a MS Project 2007 Add-In that has some code which connects to SAP and
a Database. I need the addin to read from configuration, but it is
mandatory that config is encrypted so the users (internal) cannot get to the
connection strings. I have created a Setup project, which I have tried
several solutions that I have found out in the community. I am successfully
encrypting a section in the application config during the Windows Install,
but when the installation launches the VSTO, the following error occurs:

*****************************************************************************
Name: EncryptionInstallTest
From: file:///C:/Program Files/ProjectAddinSetup/EncryptionInstallTest.vsto
File, EncryptionInstallTest.dll.config, has a different computed hash than
specified in manifest.
************** Exception Text **************
System.Deployment.Application.InvalidDeploymentException: File,
EncryptionInstallTest.dll.config, has a different computed hash than
specified in manifest.
at
Microsoft.VisualStudio.Tools.Applications.Deployment.ClickOnceAddInDeploymentManager.DownloadAddIn(TimeSpan
timeout)
at
Microsoft.VisualStudio.Tools.Applications.Deployment.ClickOnceAddInDeploymentManager.InstallAddIn()
*****************************************************************************

I am looking for an alternative solution or a way to get the Manifest
updated after encrypting the config so that the VSTO launch does not error
out with above message. Maybe there is a better way to manage configurable
items in a solution like this?

Thanks,
Antonio