Trouble with history when using bash vi bindings on iTerm2 on Lion. (I had the same problem with iTerm when I switched to Lion.)
Hard to explain exactly, but when I hit k to go to most recent command, it pushes the cursor forward a few characters, so it's no longer at start of line. And if I then hit k again, it doesn't clear the characters before the cursor.
~/.inputrc? – glenn jackman Sep 9 '11 at 17:22