I have added both the 'short' and fqn versions of the K2 workspace as host headers to the web site.
Short: http://k2webdev/Workspace/Navigation/Navigation.aspx
FQN: http://k2webdev.gcnation.com/Workspace/Navigation/Navigation.aspx
When the user uses the Short version his worklist items are not displayed.
I know you have to select a url for workspace when you run config manager, but why should it matter?