well, currently SCIM's key sequence of switching IMEs only works in this way:
Press Ctrl -> Press Shift -> Release Shift -> Release Ctrl
and pressing in this way will not work:
Press Ctrl -> Press Shift -> Release Ctrl -> Release Shift
however, some Windows users tends to "strike" Ctrl and Shift keys together to switch IMEs, which doesn't always work in SCIM if she happens to released...
