According to the docs, Beta 2. The doc files are all dated 1/11/2006. They came out a the file "Microsoft Hands-on Labs for Windows Workflow Foundation Beta 2.msi", which came from http://www.microsoft.com/downloads/details.aspx?FamilyId=5DF74E3B-FB51-4A94-A11D-DFF70288A8BB&displaylang=en.
If you know of a later version, point me to them.
Sound like you have Beta 2.2 installed and the labs you are using were built using Beta 2. There is an upgrade document here that might be helpful for you until the labs are upgraded.