Darren,

We aren't running the site under the .NET 4.0 framework as the server doesn't support that at this time. 

What we do have in our clustered server environment is the portals directory setup as a virtual directory which points out to our file share server.  We notice that when we run the upgrade, a new Portals directory is created.  We tested in development by setting up a virtual directory for our portals directory, and the LinkClick.aspx links did not work after upgrading the site.

There was an error message in the upgrade scripts for 05.02.00.sqldataprovider where it could not drop columns in the portals table properly.

I've had similar problems, but I will say start by saying i'm new to DNN so I'm happy to say what issues I've had and see if that points you towards anything you could try - but by no means an expert in this area.

The problem dropping columns, was this on the live install or a copy you made just to test the install? Its just that I got this when I made a copy for the install but had forgot to setup and grant the new user in sql server ie I had changed the web.config to use the test database and I'm using access from the apppool IIS user, and test was under a different apppool. So I suppose I would ensure the db access is all as should be for that issue, also the filesystem access rights for that user.

I'm not certain if that web.config parameter is for the .net version or something combined with what version it was compilled under, I read somewhere else that perhaps it could now be ommitted as it was there for an old issue - you could try removing it and seeing what the result is?

Have you tried just coping the prod install to a local box and attemping the upgade without the complexity of the the fileserver share, perhaps narrow it down that way?

Best of luck anyway