Thanks for your quick response Joe.

If you are referring to the ouputCaching & moduleCaching sections under:

<sectionGroup name="dotnetnuke">
<section name="moduleCaching" requirePermission="false" type="DotNetNuke.Framework.Providers.ProviderConfigurationHandler, DotNetNuke" />
<section name="outputCaching" requirePermission="false" type="DotNetNuke.Framework.Providers.ProviderConfigurationHandler, DotNetNuke" />

Yes then they are present.

I ran a comparison between the untouched release.config and production web.config file using UltraCompare and the only differences (which should be correct) are the following:

<add name="SiteSqlServer" connectionString="xxx" />
<add key="SiteSqlServer" value="xxx" />
<add key="InstallationDate" value="xxx" />
<machineKey validationKey="xxx" />

For security reasons I obviously replaced the real values with "xxx" in the example above.

The normal procedure I follow when doing an upgrade with regards to the web.config file, is to use the new release.config as my basis, copy the connection strings, machine keys and installation dates over and then rename the release.config as web.config making sure I keep a backup of the old web.config.

So I still at a bit of a loss here.
Thanks in advance.