Check which ports are open to the outside world. Helps make sure that your firewall rules are working as intended.
One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.
I wouldn't be surprised if you had problems using a v6.0 client to access the document library on a v8.0 GroupWise System, but no, as long as both the Client and Server components are v8.x, there shouldn't be a problem.
Have you tried a re-install of the client? If some client-side component got munged, that could explain the issue.