Start Firefox in Safe Mode {web link} While you are in safe mode; Press the Alt or F10 key to bring up the tool bar. Followed by;

Windows; Tools > Options Linux; Edit > Preferences Mac; application name > Preferences

Then Advanced > General. Look for and turn off Use Hardware Acceleration.

Poke around safe web sites. Are there any problems?

Then restart.

Thanks for the response, Fred. I have had hardware acceleration turned off throughout, so the solution is not there. I have verified by doing what you advised.

Did you poke around safe web sites in safe mode?

Fred: I did not think it necessary since I found hardware acceleration was not switched on. However, I just tried it and locked up in safe mode after about 20 minutes or so, same as in regular mode.  :(

Did you get any error message / crash report / anything?

No, nothing. Suddenly slows down then, within a few seconds, it locks up with the little wheel spinning in place of the cursor.

It could be the work of one of your add-ons, or even add / mal-ware. Look thru your add-ons list and make sure you know what each one is and what it does. Also, check the programs that are on your computer

Windows: Start > Control Panel > Uninstall Programs. Mac: Open the "Applications" folder Linux:

• Ubuntu Unity {web link}
• Xfce: Applications Menu category sections
• options depends on the package manager and the desktop environment

Go thru the list. If you find something that you don't know what it is, use a web search.

Troubleshoot Firefox Issues Caused By Malware {web link}

Thank you Fred. All of my add-ons are known to me and installed by me. The Troubleshoot link looks very promising so I will work through the suggestions. Seeing if any solve the problem may take some time but I will try to post a result in due course.

After working through the trorubleshooting instructions the issue seems to have all but disappeared. I get the odd freeze still but they are now few and far between. As you have to wait to see if it works I regret I cannot say what specifically solved the problem. I do try to clear my cache regularly now also.

Thanks again.

Good to hear. If you have any more troubles, Just ask another question. Happy Computing.