Your profile got changed when you installed Firefox 4 or 5. Probably the best thing to do would be to back up your bookmarks and make a new profile. You can then put the saved bookmarks back into the profile afterwards.

Maybe I wasn't clear, or maybe I don't understand the connection between what you are calling my profile and why, after working fine for 6 or 8 months before my hard drive failed, and working fine for several months after I installed my new hard drive and re-installed Firefox 3.6, I am suddenly seeing "Not Responding) messages, and experiencing hesitation and lagging when browsing on websites.

I'd appreciate if you could either explain the connection between my profile and this hesitation problem, or explain what might cause the hesitation/lagging/"not responding" issue other than this profile you're talking about. Thanks

Did you not have problems after going back to 3.6.23 after using FF 5? A possible reason for that is the changes made to files in the Firefox profile by version 5.

After I loaded 5.5, then removed it and loaded 3.6 again, I had no problems. Then my hard drive died and I installed a new one. Then I downloaded ONLY 3.6 since I already knew I didn't like the changes that 5.5 had made and the kinks hadn't been ironed out. That was in July.

The hesitation problem started recently, toward the end of Sept. I have wireless cable modem that runs 36-54 mbps but in Sept/Oct I was visiting family and distance from their router sometimes meant running at 12 or 24. I thought the hesitation/lagging was due to that. BUT Since coming home in mid Oct., although nothing about my home connection has changed, I am finding this lagging/not responding/hesitation problem continues AS IF the connection were slow but router/modem/internet connection are all intact. This is what made me wonder if anyone else is experiencing this/reporting it to Firefox. Apparently not.

Maybe it is time for some troubleshooting.

• https://support.mozilla.com/en-US/kb/Basic%20Troubleshooting