Spellbound for firefox 1.5.0.1

Spellbound is a spell checker extension for firefox. Currently released spellbound only work with 1.0.. versions. I have 1.5.0.1 and released spellbound was not working on it. After googling i found http://forums.mozillazine.org/viewtopic.php?t=351130 where a development version is placed which works fine with 1.5.0.1.