The magic key Ctrl+Space doesnt always work with SCIM. Too tired with SCIM, I decided to remove it and install ibus, ibus-qt, ibus-unikey (for typing Vietnamese). Then, I start it with:
$ /usr/bin/ibus-daemon --xim &
Then I try press Ctrl+Space to trigger but it doesnt work, even it quits itself sometimes.
The hotkey problem also occurs with KNotes. I have set Global Shortcut for some functions such as New Note, Show All Notes. And it works only once in that session. If restart machine, those shortcut is useless.
My system is Slackware 13.0 with KDE.
Hope for helps. Thanks for advance.