To solve this problem, you need to change the key binding of ATOK or CotEditor.
=> Key Bindings preferences
If you get frequent crashes of CotEditor under certain circumstances, please email a crash log to the following address:
When you send a crash log, don't forget to include the following information:
You can display a crash log by clicking Report (on 10.4) or Submit Report (on 10.3) in the dialog which appears on the crash. (There is no point to send the crash log to Apple, so just close the window after copying the log.)