This isn't obvious, because the default input is "scim" and the one you need is "scim". (yes, they're the same--I explain below)
- Install alternate language support [for example Japanese]
- Can do at install, but there is also Applications > Add/Remove Software. Look towards the bottom for "Languages"
- Expand your language, there may be extra features. For example, Japanese has an input pad, and *maybe* handwriting recognition if I can find it... (next how-to?)
- Packages such as scim.x86 should be installed then. To double check, open a terminal and $ yum info scim <== check for "Repo: installed"
- System > Preferences > Personal > Input Method
- The default setting is "Follow the system-wide configuration[SCIM]". Wrong scim. No panel switcher applet.
- Bottom choice: Use custom input method "scim". <== that's the right scim
- Log out / log in to restart gnome
- Upper right corner: right click > SCIM Setup
- Customize how everything works here.
- For a Japanese keyboard (if set up in Gnome correctly), the traditional language input switch keys can be enabled by FrontEnd > Global Setup > Next input method [...] > Key code [...] > (press the key you want) > Add
- A warning message may appear about settings not taking place, but for me all settings were enabled correctly.
! It may take you some experimenting with SCIM setup to suit your liking, but once it is setup you need not mess with it again. enjoy