Solutions to common Firefox 1.5 problems

Troubleshooting Firefox problems - Tips to prevent Firefox issues like hanging, reduce memory usage

Common issues associated with Firefox 1.5
1. Sometimes when you try to restore or maximize a Firefox browser window, Firefox doesn’t respond to either mouse clicks or Alt+Tab keys. This is generally due to a memory leak. All you can do is either rightclick the minimized Firefox tab in task bar and click “Close” or kill the firefox.exe process from Windows Task manager and restart Firefox.

2. Did you ever experience Firefox 1.5 crash with the Dr. Watson (drwin.exe) error ? Yes, SessionSaver extension remembers all text your typed in an input text field and saves all open browser tabs in the event of a session error but SessionSaver is not yet ported to Firefox 1.5

3. Firefox may freeze for a moment and then run normally. If you click a hyperlink in Outlook email, Firefox takes a long time to open the webpage and also becomes slow. Or Firefox won’t launch until an existing “firefox.exe” process is killed manually from Task Manager. Sometime if you drag and drop some text on the search bar, Firefox will need be restarted.

Smooth browsing with Firefox - Here, in this guide, we will discuss tips and methods to speedup Firefox launch time, save your Firefox 1.5 from freezing unexpectedly and preventing Firefox crashes.

If Mozilla Firefox hangs as soon as you launch the browser, the issue is probably either with an installed extension or a theme. Try running Firefox in Safe Mode (firefox.exe -safe-mode) - If it runs normally, disable or uninstall the problem causing theme or extension.

Firefox can hang is there is a memory leak. Installing too many extensions or opening lot of browser tabs can hog memory. Disable all extension that you haven’t used since the past week

Sometimes, my Firefox returns an error when I try to download and save pictures from my Yahoo Photos webpage. The problem disappears when I clear download manager history. The memory usage increases greatly after downloading files unless the Download box is ‘cleaned up’ after they finish downloading. To do this automatically, change the download manager’s history setting to remove files from the download manager “upon successful download”.

The Back and Forward button caching functionality -which speeds up the display of recently viewed Web pages can also contribute to memory problems. Disable the fast back/forward caching (bfcache) feature by setting browser.sessionhistory.max_total_viewers to 0 using about:config.

Adobe Reader browser plugin can consume huge amounts of memory. To disable the Adobe Reader Firefox plugin, open the Firefox plugins directory and delete or rename the nppdf32.dll file.

Firefox can also crash when you close a tab that is loading or playing a Java Applet - Always disable Java plugin, it will also reduce the CPU usage.

In certain configurations, disabling Mouse Gesture in Firefox helps curb memory spikes.

Don’t install Adblock extension with Firefox 1.5 as it causes an increase in Firefox memory usage. Instead use AdBlock Plus.

Setting the browser history to extremely large values will increase memory usage. Keeping the history to a reasonable level is a good idea for this reason.

Install FasterFox tweaking extension - it allows you to prefetch links and tweak many network and rendering settings such as simultaneous connections, pipelining, cache, DNS cache, and initial paint delay.

config.trim_on_minimize - If you experience slow startup after long periods of inactivity (minimized Firefox window or other), it is because the Microsoft Windows Operating System reclaims the memory Firefox used in anticipation that other open applications might need it. This can cause a delay when Firefox is restored. Therefox, you can set the config.trim preference to disallow Windows to reclaim memory from a minimized Mozilla application. Always set config.trim_on_minimize to true in Firefox

Other about:com changes to speed up Firefox:

1. Disable prefetch: go to about:config. Search for prefetch, you’ll find network.prefetch-next. Double click it to turn it false if it is on.

2. Limit the memory cache: about:config, new integer, browser.cache.memory.capacity, set it to the memory in KB you want to limit the memory cache to.

I hope these tweaks improve your web browsing experience with Firefox. One last thing, Mozilla has published a list of situations that can lead to massive memory leaks and slow down computers. You can use this to diagnose problem with individual web pages.

• Bad live bookmark causes Firefox memory usage to grow endlessly and make the browser unstable


• Memory leak (especially in graphics-intensive webpages), freed upon minimize


• When saving a picture, HUGE memory leak! Also slows machine down!


• memory leak if page contains a refresh meta-tag


• Memory leak when I leave firefox up with a few sub tabs open


• Firefox begin to eat memory and hangs after opening this URL


• very slow restore from minimize after memory growth compared to other applications

About memory leak - a process that over time can gradually eat away at system resources. In worst-case scenarios, a memory leak could cause an application to become unstable.

Essential Firefox Tweaks References: 1 | 2 | 3