As a work-around for bug ZBX-1118 we added a dummy hostgroup on the master server.
And it seems to work.
You can select the node (master or slave80) and then the hostgroup is shown on the "Latest Data" page.
First of all, all data for every host are shown, which is bad and a bug by itself in 1.6. And second, as soon
as you try to select one host, the selected node is switched back to the master node where no data is shown
because no host in that dummy hostgroup.
And then you can select the node slave80 and start over.