When typing in an IME (Japanese for us, but we're assuming it happens with other IME as well, like Mandarin, Korean, etc) text gets inserted before it's chosen. When typing something into an IME, you type out the sounds to get the words you want in that other language. It shows a list of possible matches, and you hit space to move down the list and then enter to choose the one you want.

Every time you hit space, though, it inserts that word into the text area, meaning you are writing things you don't want to write.

This doesn't happen every time, though. Usually the first time someone inputs a word with the IME it works correctly. The second time is when it breaks and tries to put in everything it can. When you choose the first item on the list, it duplicates it showing it twice.