I have the following values in my Xmodmap file, which is loaded on startup:

keycode 21 = asciicircum bar
keycode 51 = bracketright braceright
keycode 34 = at underscore
keycode 19 = 0 backslash
keycode 49 = grave

All of the keys work except for the keycode 49. I don't get it! I press it and nothing happens! I have set my keyboard to use a Japanese layout since that is what I am used to with the few changes above.

xev reports that when I press the grave key keycode 49 is being returned so it looks like the key works.

Any ideas?