Lion Server, VPN and Time Capsule as Router Issue

Well, today I upgraded all my machines to Lion and the experience overall was pleasant. Since I had 4 machines to upgrade, rather than downloading the install 4 times I was able to save the install to a flash drive. I was able to copy the installer to the flash drive so I can copy to the other machines (this can only be done before installing right after the download is complete from the app store - app is in Applications folder).

Anyways getting down to the point. Once I was done, I purchased and downloaded Lion Server for my mac mini so I can enable the VPN services. This should really be an easy 1-2-3 click process but the VPN would fail outside of the network (which is where we needed it to work).

The admin tool set up my Time Capsule (Airport Extreme) base station appropriately as far as ports to open. For 2 hours I was beating my head into a wall trying to figure out why the requests would not pass thru to the server from an external request. I tried many different things from opening other ports, setting a default host etc. But the issue lies in the latest firmware for the stations (7.5.2). I was finally able to find that information in the apple support forums. So I went ahead and downgraded my station to firmware 7.4.2 and everything worked fine. You can easily do this by following these steps:

1. Launch AirPort Utility found in Applications>Utilities>Airport Utility
2. Click on the base station you want to downgrade from the sidebar (left column of the window)
3. In the Menubar select 'Base Station'
4. Select 'Upload Firmware...'
5. Select ‘7.4.2'
6. Select 'OK'

Do that and then try your VPN connection and Voila! It works! Thank you apple for wasting 2+ hours of my day.

UPDATE!!!!

For this to work on 7.4.2+ make sure you do not have any accounts set in your Back to My Mac settings on the station!