the window of "preferences" can not be closed when you click "close" icon first time under certain conditions.

1.File->Preferences->Migration->MySQL to CUBRID, then the type table is appeared.
2.click the field where can be edited(e.g. the filed under "Target Data Type"), then click the "close" icon to quit the window, but it doesn't be closed.
3.move the mouse pointer on right field of the window or resize the window, some contents will be disappeared.
4.then click the "close" icon, at this time you can close the window.