After Yong Li's comment on this issue, I gave it another try, and it
works, well, partially.
After modifying the /usr/lib/im/htt.conf file, I can finally type
Hiragana within gedit, but I can't convert it to Kanji.
When I do Ctrl-space and type a-k-a, and I hit space, nothing happens.
Then I see these entires in /var/log/messages
Mar 1 08:40:22 hydro htt_server[19364]: Invalid message(IC normal
state):43
Mar 1 08:40:35 hydro htt_server[19364]: Invalid message(IC normal
state):73
Mar 1 08:40:35 hydro htt_server[19364]: Invalid message(IC normal
state):73
Mar 1 08:40:37 hydro htt_server[19364]: Invalid message(IC normal
state):13
Mar 1 08:40:37 hydro htt_server[19364]: Invalid message(IC normal
state):13
Mar 1 08:40:37 hydro htt_server[19364]: Invalid message(IC normal
state):73
Mar 1 08:40:37 hydro htt_server[19364]: Invalid message(IC normal
state):43
Mar 1 08:40:53 hydro htt_server[19364]: Invalid message(IC normal
state):43
Mar 1 08:40:59 hydro htt_server[19364]: Invalid message(IC normal
state):73
Mar 1 08:40:59 hydro htt_server[19364]: Invalid message(IC normal
state):43
Mar 1 08:41:16 hydro htt_server[19364]: Invalid message(IC normal
state):13
What I *can* do is convert Hiragana to Katakana by hitting the
arrow-down key. This works as expected.
I also tried with LANG=zh_CN.UTF-8. Now this seems to work just fine.
I've typed several Chinese characters in simplified Chinese, and it
works flawlessly. Hmm.. This makes me jealous. ;)
Kohei