I also have been experiencing the same problem as the OP. Google services including Google Search, GMail, and YouTube are all intermittently inaccessible through the most… (read more)
I also have been experiencing the same problem as the OP. Google services including Google Search, GMail, and YouTube are all intermittently inaccessible through the most recent version of firefox on my MacBook Pro running OS X 10.6.8. Additionally, sites that use Google APIs also hang (sometimes) when they try to load.
This is frustrating to me because I depend on these services for much of what I do on the web. It is especially frustrating because Firefox has been a dependable and useful browser for me for years. I have had to start using chrome as a workaround but would really prefer to stick with Firefox.
I have identified this problem as specific to firefox, as I have no issues with the Google services in Chrome or Safari. I am also always able to get normal pings to https://www.google.com and https://www.gmail.com through Network Utility on my Mac.
I have tried all of the above solutions including - clearing the cache and cookies (like a zillion times by now) - disabling and deleting all add-ons - starting firefox in safe mode - deleting firefox and reinstalling from a freshly downloaded dmg - manually deleting the user profile for firefox from Library - Changing the manual proxy setting to NO PROXY in firefox preferences - removing all trusted add-ons from firefox preferences - Pushing RESET in the about:config dialog - Resetting my modem/router
I tried to adjust the keyword setting in about:config but when i searched for it it was not present. I wonder if this is part of the problem.
Additionally I have removed the Auto-update files that google software like google earth use to call home to check for updates.
None of these have resolved the issue. I still can only sometimes access Google services using firefox. If I am logged in to GMail using Firefox, i will at some point lose connection and be unable to reestablish the connection for an indeterminate period of time.
This problem has been going on longer than a week or two, maybe a month. I don't know what to do to resolve the issue.
I believe there must be something broken in the way Firefox handles requests for google sites that I have not yet been able to reset or change.
Please, if anyone has found an actual, permanent solution, respond to this thread.
(this seems to be similar to the problem described in another Mozilla support thread: https://support.mozilla.org/en-US/questions/963648 )