Hello, I use mozc (a Japanese input method editor) on Linux to type in Japanese. With this kind of input method, you can press on the space key to go from hiragana to kanji. For example you type ふるい, then press space, and it becomes 古い. But I got this problem: when I press the space key the background becomes black and I can no longer read! Please see the attached screenshots. I come across this behavior only with Firefox (not with any other GTK app such as Deluge or GIMP). The problem is not resolved by making Firefox ignoring my GTK theme (see https://askubuntu.com/questions/8336/how-can-one-make-firefox-ignore-my-gtk-theme-entirely ). Do you have any idea where my problem is coming from? Best wishes, Sylve