Hello Vibhas. Although possibly not related to your problem, I will remind you that the version of Firefox you are using at the moment has been discontinued and is no longer supported. Furthermore, it has known bugs and security problems. I urge you to update to the latest version of Firefox, for maximum stability, performance, security and usability. You can get it for free, as always, at [http://www.getfirefox.com getfirefox.com]. As for your problem, you may be having a problem with some Firefox add-on that is hindering your Firefox's normal behavior. Have you tried disabling all add-ons (just to check), to see if Firefox goes back to normal? Whenever you have a problem with Firefox, whatever it is, you should make sure it's not coming from one of your installed add-ons, be it an extension, a theme or a plugin. To do that easily and cleanly, run Firefox in [http://support.mozilla.com/en-US/kb/Safe+Mode safe mode] and select ''Disable all add-ons''. If the problem disappears, you know it's from an add-on. Disable them all in normal mode, and enable them one at a time until you find the source of the problem. See [http://support.mozilla.com/en-US/kb/Troubleshooting+extensions+and+themes this article] for information about troubleshooting extensions and theme. You can troubleshoot plugins the same way. If you want support for one of your add-ons, you'll need to contact its author.