Comment 24 for bug 66015

Well I couldn't get it to work but for the person who wants to take up the challenge I think the key is to place the code:

    for (i in list) {
    if (list[i].indexOf("_") != -1) {
        list.splice(x, 1)
      }
    }

at line 204 in toolkit/content/toolkit/content/inlineSpellCheckUI.js

This should remove the items in the list that have an underscore in them, however I couldn't get it to work