Dark themes often makes Firefox kind of useless when updated on a Linux system. This is a fix which is used to remove black text on black fields, forms and checkboxes. Instead your new Firefox 3.* (and of course Swiftweasel), gets a BEAUTIFUL appearance when using a dark theme. You need to use this style together with Modified Firefox Forms , so install them both. You also need to replace your Firefox forms.css with this one http://gomellow.com/stuff/firefox3/forms.css . A more extensive guide on the whole issue can be found -> http://www.gomellow.com/?p=32.