In gnome-terminal, selecting Gnome Terminal Users Guide on
the Help menu does nothing at all. This is in the latest
Rawhide release I found (gnome-core-1.0.39-11). Haven't
confirmed that the problem is also in the 6.1 release
version but it's likely.
This has now been fixed. Try the newer gnome-libs packages (gnome-core 1.0.54)