Start Firefox in [[Safe Mode]] to check if one of the add-ons is causing the problem (switch to the DEFAULT theme: Tools > Add-ons > Themes). * Don't make any changes on the Safe mode start window. See: * [[Troubleshooting extensions and themes]] * [[Troubleshooting plugins]] If it does work in Safe-mode then disable all extensions and then try to find which is causing it by enabling one at a time until the problem reappears. * Use "Disable all add-ons" on the [[Safe mode]] start window to disable all extensions. * Close and restart Firefox after each change via "File > Exit" (Mac: "Firefox > Quit"; Linux: "File > Quit") ---- There are also other things that need attention: Your above posted system details show outdated plugin(s) with known security and stability risks that you should update. *Java Plug-in 1.4.2_03 for Netscape Navigator (DLL Helper) Update the [[Java]] plugin to the latest version. *http://www.oracle.com/technetwork/java/javase/downloads/index.html (Java Platform: Download JRE)