Confirmed on(K)Ubuntu 9.10 karmic, MacBookPro5.1, international US keyboard. As suggested at #33, the following command solves the issue, at least for the internal keyboard.
$ xmodmap -e 'keycode 94=grave asciitilde grave asciitilde dead_grave dead_horn' -e 'keycode 49=section plusminus section plusminus section plusminus'
Confirmed on(K)Ubuntu 9.10 karmic, MacBookPro5.1, international US keyboard.
As suggested at #33, the following command solves the issue, at least for the internal keyboard.
$ xmodmap -e 'keycode 94=grave asciitilde grave asciitilde dead_grave dead_horn' -e 'keycode 49=section plusminus section plusminus section plusminus'