Error: TF80012 with side-by-side installation of VSTS 2005 and 2008

I have a 2003 server that I use to demo VSTS. I initially installed the 2008 TFS and Team Suite RC (which was only available on a limited scale so don't ask me where you can get it). Later I installed 2005 Team Suite with Team Explorer so that I could demo that as well. When I was in a Work Item query window and I highlighted multiple Work Items and then opened them in Excel or Project I received the following error:

TF80012: The document cannot be opened because there is a problem with the installation of the Microsoft Visual Studio 2008 Team Foundation Office integration components. Please see the Team Foundation Installation Guide for more information.

I learned from Mareen Philip from Microsoft that there is an issue with running the two side-by-side that will not be fixed for the RTM later this month (but they are working on a patch for it). The following information will be included in a Read Me that will ship with the RTM:

You can only use one version of Team Explorer to work with Microsoft Excel and Project. The latest version you installed is the version that will open Microsoft Excel and Project correctly. You can continue using that version, or you can switch to the other version by using one of the following procedures.

To register the Visual Studio 2008 version of Team Explorer to use the Microsoft Excel and Project add-ins

1. At the command prompt, change directories to:

   Program Files\Microsoft Visual Studio 8\Common7\IDE\PrivateAssemblies
   

2. Unregister the 2005 version of the add-in by running the following command:

   regsrv32 /u TFSOfficeAdd-in.dll

1. At the command prompt, change directories to:

   Program Files\Microsoft Visual Studio 9\Common7\IDE\PrivateAssemblies\
   

2. Register the 2008 version of the add-in by running the following command:

   regsrv32 TFSOfficeAdd-in.dll

To register the Visual Studio 2005 version of Team Explorer to use the Microsoft Excel and Project add-ins

1. At the command prompt, change directories to:

   Program Files\Microsoft Visual Studio 9\Common7\IDE\PrivateAssemblies
   

2. Unregister the 2008 version of the add-in by running the following command:

   regsrv32 /u TFSOfficeAdd-in.dll

1. At the command prompt, change directories to:

   Program Files\Microsoft Visual Studio 8\Common7\IDE\PrivateAssemblies\
   

2. Register the 2005 version of the add-in by running the following command:

   regsrv32 TFSOfficeAdd-in.dll

You may also receive this error after you uninstall one of the versions of Team Explorer. To fix that scenario do the following:

Repair the installation of Team Explorer by using the following procedure.

1. Open the Control Panel.
2. If you are using Microsoft Visual Studio 2008 Team Explorer select this entry in the control panel. Otherwise select Microsoft Visual Studio 2005 Team Explorer.
3. Click Change/Remove.
4. In the Setup dialog box, select Repair or Reinstall.
5. Click Next.
6. In the Ready to Repair page, click Repair.