Hello grizzler,

Try to Turn off hardware acceleration, and check it again (in safe mode hardware acceleration is disable).

Try to Change the home page Try to Change how windows and tabs are loaded Try to Check your antivirus software

Please let us know if any of these tips solve your problem

Thank you

Makes no difference, I'm afraid.

A possible cause is security software (firewall,anti-virus) that blocks or restricts Firefox or the plugin-container process without informing you, possibly after detecting changes (update) to the Firefox program.

Remove all rules for Firefox and the plugin-container from the permissions list in the firewall and let your firewall ask again for permission to get full unrestricted access to internet for Firefox and the plugin-container process and the updater process.

See:

• https://support.mozilla.org/kb/Server+not+found
• https://support.mozilla.org/kb/Firewalls

Create a new profile as a test to check if your current profile is causing the problems.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer some files from an existing profile to the new profile, but be careful not to copy corrupted files.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Look at my original post. A new profile has already been tried. And even though I fail to see how disabling the firewall could affect building and traversing Firefox's menus (which is where the slowness is most annoying), I switched off iptables just to be sure. No change of course.

Sorry about those suggestions. I appear to have missed that you are on Linux.

Any luck with disabling IPv6?

• http://kb.mozillazine.org/Error_loading_websites
• http://kb.mozillazine.org/Error_loading_websites#IPv6

The setting network.dns.disableIPv6 has been set to true for ages.

It's JavaScript/Flash. I just tried 18.0.1 and it seemed acceptable at first. But after the first Flash movie the same slowness crept in (bookmark menu taking seconds to open, traversing the menu with the highlighted item lagging up to five items behind the mouse pointer). Could be that new JavaScript engine is broken in some way or simply requires much more 'horse power'. Back to 17...

hello, maybe it's an issue with the protected mode in the flash plugin - you could try if downgrading to flash 10.3 (which is still supported) or disabling protected mode makes a difference.

Downgrading didn't make any difference and neither did disabling protected mode (assuming adding the command mentioned to /etc/adobe/mms.cgf did the trick).

Thanks for your suggestions anyway.

I have same problem, firefox 17 was fine, firefox 18 crawls on my Ubuntu 12.10 system. On many actions. At first I thought I was having DNS issues. But now see that many others are reporting same slow response.

Enter a URL and it takes forever to respond with the web page.

Click on a field to enter some kind of data and it can take 5-10 seconds before the keystrokes appear in the web form.

Sometimes my system's display actually dims briefly waiting for responses.

Chrome has NO problems like this on the same system.

I guess I'll downgrade back to v17 Firefox until I see some indication the current v18 problem(s) are resolved.

I too have this problem, and it is only since the update. no other setting has changed on my PC. I am running Win XP32 on this PC.

It is infuriating to the point of thinking about the I word (Internet Explorer)

I should state that I see the same "slowness" on Windows so this is NOT a Firefox on LInux problem... at least from what I can see from multiple machines I use that are a mix of firefox on windows or linux.

I am more than a little annoyed to find this thread somehow got marked as 'solved'. Apparently the reply by madperson was entered as 'chosen solution'. I did NOT do that and I have removed this 'solution' as this issue is by no means solved!

You did try a clean profile with out modifications and not by using a reset?
A reset still tries to import some data from the old profile and can cause problems.

Create a new profile as a test to check if your current profile is causing the problems.

See "Creating a profile":

• https://support.mozilla.org/kb/profile-manager-create-and-remove-firefox-profiles
• http://kb.mozillazine.org/Standard_diagnostic_-_Firefox#Profile_issues

If the new profile works then you can transfer some files from an existing profile to the new profile, but be careful not to copy corrupted files.

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

There is definitely something wrong with the Menu / Bookmark code. After "upgrading" to 18.0 the Bookmarks menu became incredibly slow. I find it's pretty easy to replicate this issue: All you have to do is open the Bookmarks menu and navigate around for a bit - you don't even have to open anything. After a while the Bookmarks menu will take 3 seconds to open and also there is a ton of lag when you're navigating around the bookmarks - IOW the highlighted selection is nowhere near where the mouse is and it takes a while for it to catch up. It even does this in Safe Mode so it's definitely not related to any plug-in. I hate to say it, but it might be time to start using Google Chrome full-time... My coworkers and I already have to use it (Chrome) at work due to the heavy use of JavaScript with the tools we use and FF is just too slow in comparison.

Hi Inc0gnit0

Did you try to delete the places.sqlite database file?

You can check for problems with the places.sqlite database file in the Firefox Profile Folder.

• http://kb.mozillazine.org/Bookmarks_history_and_toolbar_buttons_not_working_-_Firefox
• https://support.mozilla.org/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file

It's definitely Firefox 18.0 that's broken, not our profiles. Fedora 17 64bit here - all I have to do is start Firefox, go to Pandora and let it play and my Bookmarks/menus get stupid slow. I tried every suggestion under the sun (listed here and Googling), nothing helped.

All I had to do was go get the older 17.0.1 RPMs from koji.fedoraproject.org, do a quick downgrade and boom - everything is fast again. No other changes, it's that easy and quick to get rid of this problem.

rpm -Uhv --oldpackage firefox-17.0.1-1.fc17.x86_64.rpm xulrunner-17.0.1-3.fc17.x86_64.rpm

Now everything is back to normal and I've blacklisted the upgrade until someone at Mozilla figures out what they broke and fixes it.

I have the same problem: Firefox 18.0.1 on a Ubuntu 10.04 has gone incredibly slow. _ONLY_ system change: upgrade to 18.0.1.

The system (2.4GHz single cpu, 1Gb RAM) goes from about 2% CPU load to 100% as soon as i click on 'bookmarks'. The response time on a bookmark is between 3 seconds on a freshly started browser, up to 20 sek at 100% CPU load, when the browser have been in operation for roughly an hour+ Memory use remain unchainged around 400Mb.

Sorry lads, i guess this lemon belongs in your lap. I am an absolutely abysmal programmer, so i cannot look into the code myself.

Just tried 18.0.2 and like 18.0.1 it seemed to be a little less slow at first, but as soon as I started to do some serious browsing and opening bookmark (sub)menus, it started to crawl again. And I'm still running with only a minimal add-on set-up. So, still broken... :(

Confirmed. 18.0.2 has the same issue.