ASP Sate Service configuration over a Web Farm Cloud, working on IIS Express or IIS7+

I am dealing with a very simple issue, but could not made it work. I am using just for testing and learn about it IIS Express, but the same behaviour could be found in IIS7. I have 2 web projects, both are the same, based in 1 aspx page wich sets and reads a Session value. The web.config shown below, states the session state to be ASP net session service (service is up, working fine).

web.config

    ...
    <machineKey
     validationKey="336EFFFE3352F63FEF22AEA4F9458B90C77DA3CCD3B191D3814F2FB6B1019B80D7BEA58D526DC741177AA401FDAAA334D54511B293B2F0503D6AC1A5110C3982"
      decryptionKey="E059A08E40C4437026686D958FD23A61FC5A4BA31E982B0F"
      validation="SHA1"
      decryption="Auto"/>
     ...
    <sessionState mode="StateServer" 
                  timeout="10" 
                  stateConnectionString="tcpip=127.0.0.1:42424" 
                  stateNetworkTimeout="40" />

So As you can see, I have both settings, for the 2 web sites equally configured. After testing I have also checked that I receive both same session id's from web explorer's. As seen in the image I could not make both get the same values for the session when asked to the ASP net session service provider.

Any ideas why and how this could be solved would be much more than appreciate it. I have been reading about Web Farm configuration, create the same ID's, etc. But I have found that this is also not working, apart that there is a violation regarding IIS settings. Many thanks.