Many site issues can be caused by corrupt cookies or cache.

Warning ! ! This will log you out of sites you're logged in to. You may also lose any settings for that website.

• Delete cookies to remove the information websites have stored on your computer {web link}

• How to clear the Firefox cache {web link}

If there is still a problem,

Start Firefox using Troubleshoot(Safe) Mode {web link}

A small dialog should appear. Click Start In Troubleshoot(Safe) Mode (not Refresh). Is the problem still there?

While you are in Troubleshoot(Safe) mode;

Try disabling graphics hardware acceleration in Firefox. Since this feature was added to Firefox it has gradually improved but there are still a few glitches.

How to disable Hardware Acceleration {web link}

Thank you, FredMcD, for you detailed reply. I have been working through the suggestions you posted, and had cleared the cookies and the Firefox cache.

Then I went into Quora from my Chomebook, which uses the Chrome browser. This appeared to do exactly the same thing occasionally.

Although Firefox is my favourite browser, I decided to try accessing Quora using Chrome on my Windows PC. After a couple of days, this also did a similar trick, using large amounts of CPU and going nowhere. I suspect that the scripts built in to the home page for Quora have got some form of timing race in them. If I get passed the home page, I have no issues continuing around the site. Even going back to the home page within the same browser session doesn't seem to cause a problem. If I enter the full address of one of the other pages on the site to start a session, so far I have not experienced any issues either.

When it does hit my problem, if I close the Firefox window with the 'x' button (top right), Windows task manager shows 3 Firefox processes that continue running for at least 30 seconds and consuming significant amounts of CPU time.

The operation of the Quora site is changing fairly frequently, presumably as different contributors make modifications. It is that sort of site. I will see if I can find a support channel for the site and raise the issue with them.

Thanks again for replying to my question.

. . . if I close the Firefox window with the 'x' button (top right) . . . .

Try this instead: Windows: Menu > File => Exit Mac: Menu > Firefox => Quit Firefox Linux: Menu > File => Quit

When you press the X (top right of the window) it only closes that window.

Sorry, I didn't make it clear. I only had one Window running. I noticed that the PC seemed sluggish after closing that Window so I launched Task Manager, and that was when I could see the other processes were still apparently running. They did terminate eventually by themselves after which the PC was working normally.

If I hadn't opened Task Manager I probably wouldn't have found the three processes, which did not have any apparent Windows open. However, I had found that closing the only window with the 'x' and then immediately relaunching Firefox came up with a warning that it was still running.

As I am typing this reply, I have one Firefox window with just one tab - the one I am using. Task Manager is showing Firefox running as one App and as five background processes.

Next time it happens I will try the "Menu > File => Exit" you suggest.

Thank you.

I haven't identified exactly what the problem was, and both Firefox and the Quora website have had updates made since I posted the question.

As it affected only the one site, I am inclined to think it was some faulty code from the quora.com website that affected Firefox, but not the Chrome browser.

I have not seen this problem for several weeks, so apparently my problem has been solved. Thanks for all the suggestions about the problem and possible solutions.