Korean character input (typing Korean characters) does not work on most sites.
On my MacBook, I have two language inputs that I switch between frequently. I have a US layout and a Korean input layout. When I switch to the Korean input method and begin typing, a narrow box at the bottom of my browser appears. I can type one character block, such as 야 or 돈, but any letter that would make a new character block deletes the previous block to make room, even though the bar is long enough to fit many sentences. The bar has a red "close window" button.
The bar seems to serve no purpose. I can't even copy and paste each individual character block I type.
I had this problem when I upgraded to Firefox 4. I switched back to 3 because of it, but then to Google Chrome because of speed issues. I'm trying to come back to Firefox again, but 11 versions later (Firefox 15), this same problem still exists.