This is very annoying. I write highly multilingual documents at work (English, German, French, Greek), using both the mouse and the Cmd-Space shortcut to switch between keyboard layouts. For some reason, Mac OS hangs temporarily (approx. 15 sec) if those switches are frequent. In a multilingual document, where a single phrase may easily contain individual words in two or more languages, this problem becomes nerve-wracking. The hangs do not only affect the word processor or the keyboard layout controller (i.e. the flag on the menu bar), but the entire "event loop" of the OS, which means that during those seconds I am unable to type or click in any running application. Has anyone encountered this? Information on the web seems surprisingly scarce. Thank you.