Firefox 1.0.7 used to be able to start up in Gnome 2.10.2 with this user.js file present in the profile directory. After 1.5 screwed up my profile, I removed my old one and installed with a whole new profile, after which I put back this user.js file. Firefox then promptly fails to start. Removing the user.js file solved the problem though, and 1.5 starts normally. user.js: user_pref("adblock.patterns", "/[\W\d_](hot|spy)log[_\W\d]/ /[\W_]ad(s|v|x|bot|jumper|cycle(frame)?|net|ward|trix|vert(isers|ising|s)?|view|serv(e(rs?)?)?)?[_\W\d]/ /[\W\d_](blog|central|page|side|value)ads?[_\W\d]/ /[\W\d_]at(ax|dmt|wola)[_\W\d]/ /[\W\d_](double|fast|value)click[_\W\d]/ /[\W\d_]hit[_\W\d]/ /[\W\d_]p(artner|ing)[_\W\d]/ /[\W\d_]reklama[_\W\d]/ /[\W\d_]smartserve[_\W\d]/ /[\W\d_]sp(onsor|ymagic)[_\W\d]/ /[\W\d_]top(100|cto)[_\W\d]/ /\D(728|588|468|234|120)x(600?|120|90)\D/ /[\W\d_]ban((ner)?(id|s)?)[_\W\d]/"); user_pref("allinonegest.trailColor", "#33FF33"); user_pref("allinonegest.trailSize", 3); user_pref("browser.download.dir", "D:\Downloaded Files"); user_pref("browser.download.downloadDir", "D:\Downloaded Files"); user_pref("browser.download.manager.closeWhenDone", true); user_pref("browser.download.manager.retention", 0); user_pref("browser.history_expire_days", 0); user_pref("browser.jsannoyances.disabled", true); user_pref("browser.link.open_newwindow", 3); user_pref("browser.search.selectedEngine", "Google"); user_pref("browser.startup.homepage", "about:blank"); user_pref("browser.tabs.autoHide", false); user_pref("browser.tabs.loadFolderAndReplace", false); user_pref("browser.turbo.enabled", true); user_pref("dom.disable_window_flip", true); user_pref("dom.disable_window_move_resize", true); user_pref("dom.event.contextmenu.enabled", false); user_pref("network.http.max-connections", 30); user_pref("network.http.max-connections-per-server", 8); user_pref("network.http.max-persistent-connections-per-proxy", 8); user_pref("network.http.max-persistent-connections-per-server", 8); user_pref("network.http.pipelining", true); user_pref("network.http.pipelining.maxrequests", 8); user_pref("network.http.proxy.pipelining", true); user_pref("nglayout.initialpaint.delay", 100); user_pref("plugin.disable_full_page_plugin_for_types", "video/x-ms-wvx,video/x-ms-wmv,audio/x-ms-wax,audio/x-ms-wma,video/x-ms-asf,application/x-mplayer2,video/x-ms-asf-plugin,application/vnd.adobe.xdp+xml,application/vnd.adobe.xfdf,application/vnd.fdf,application/pdf"); user_pref("security.warn_entering_secure", false); user_pref("security.warn_submit_insecure", false); user_pref("signon.rememberSignons", false);
user_pref("adblock.patterns", "/[\W\d_](hot|spy)log[_\W\d]/ /[\W_]ad(s|v|x|bot|jumper|cycle(frame)?|net|ward|trix|vert(isers|ising|s)?|view|serv(e(rs?)?)?)?[_\W\d]/ /[\W\d_](blog|central|page|side|value)ads?[_\W\d]/ /[\W\d_]at(ax|dmt|wola)[_\W\d]/ /[\W\d_](double|fast|value)click[_\W\d]/ /[\W\d_]hit[_\W\d]/ /[\W\d_]p(artner|ing)[_\W\d]/ /[\W\d_]reklama[_\W\d]/ /[\W\d_]smartserve[_\W\d]/ /[\W\d_]sp(onsor|ymagic)[_\W\d]/ /[\W\d_]top(100|cto)[_\W\d]/ /\D(728|588|468|234|120)x(600?|120|90)\D/ /[\W\d_]ban((ner)?(id|s)?)[_\W\d]/"); that block is no longer supported. Upgrade your extention and redo and all will be fine.