Yes, I'd read this one. I also played with FCITX (though it's for simplified, and I want to use traditional), and with KDE locales, system wide locales, have probably each and every Chinese font package available in the repo installed, but didn't manage to make SCIM work. It just hangs there, not doing anything.
I remember in pcc setting up keyboard to use SCIM in advances options in PCLOS 2007, but now there is no "advanced options" there to set up. I modified i18n manually to add necessary lines, but it didn't help.