Firefox 8 on windows XP, don't remember it not working.
However, I have noticed it happen in chrome..tho scrolling down in the iframe shows that the text box was too low for some reason.
Edit: just now in Chrome it didn't happen initially, but after I sent something on the next page it happened. the alt+shift+i thing didn't jump to it, tho I was able to scroll the iframe and get the text box.