Firefox does not work smoothly when it is loading any webpage. Specially, when I open new tabs and load new websites while it is still loading last website in other tab, the situation becomes worse. Main problems that occur are - page will not scroll, or scrolling hangs for a sec or so, works a little bit and it happens repeatedly, new tabs will open but not smoothly, website loading also gets affected in similar way. The dot that revolves on tabs while loading any webpage gets really annoying. It revolves intermittently. Imagine a car engine not starting, it starts, stops, starts, stops. That's what happens with Firefox. But once all webpages are completely loaded and scrolled 2 or 3 times from top to bottom of the page, then it is all good. All the problems occur when page is still loading in fore- or background in any or all of the tabs. I tried to run Firefox with all add-on and plugins disabled, tried to refresh Firefox from troubleshoot information. But nothing helps. I even uninstalled and reinstalled Firefox. I guess my laptop is not having memory issues. I am using Windows 7 x64 based system. RAM is 4 GB. All other software work well. Most importantly, Chrome has no such issues in comparison to Firefox. Also, when IDM (internet download manager) takes over some downloads, the Firefox hangs for few seconds. Please help. Thank you.