I installed Teamviewer 8 using the .deb package as downloaded. I then tested access to an adjacent Windows XP machine using the CLI:
teamviewer -i <nnnnnnnnn> <password>
And successfully connected to the target machine. Then I noticed that Teamviewer 6 appeared to still be installed on Ub10.04, as well as Teamviewer 8 (at least as far as the synaptic package manager was concerned). Therefore I uninstalled both of them (completely), but discovered that after uninstalling 6, there was no evidence that 8 was there either (although synaptic still showed 8 as installed).
Long story short: I misread a CLI message as "must be run as root", which was in fact "must not be run as root".
Now, version 8 is solely and correctly installed under 10.04, and working flawlessly with remote Windows XP target machine, including a successful switch of control between the two desktops. However, it does appear that the previous version must be uninstalled before installing the new one.
