Thanks to Ariel Canievsky for sending this in. Ariel says:

Do you remember the old VB6toVB5 downgrader tool posted at your page? I was a frequent-user of it, until I buy VB6.

Nowadays I've been facing a similar problem. I'm working on a project in VS2008, and the mid-client needs a VS2005 version since they (still) don't work with VS2008. So, this post saved my life: Downgrade a VS 2008 .sln or .csproj to VS 2005.

Ariel also found a downgrader utility here.