That is your choice, but remember Firefox 3.6 will not be supported for much longer.

How much of that bloat will be your chosen software extensions to Firefox.

If you have a specific identifiable and reproducible problem,

• especially of you think it makes Firefox 10 bad in comparison with Firefox 3.6
• and it relates directly to Firefox

why not politely share that knowledge. The problem may even have a solution or a workaround.

I have the same add-ons in 3.6 that I had in Version 10 - Adblock, Garmin Communicator, Java and Microsoft Dot Net, but 3.6 loads about five times as fast, and shuts down instantly.

Version 10 loads glacially slowly, and, often, when I shut it down, it's still doing something on my disk drive two minutes later, preventing me from re-starting it.

As I said - it's a piece of crap!

I'll run 3.6 until it won't run any more, and then switch to something else.

I do not tend to use that software, but I certainly do not see that sort of behaviour in Firefox 10.0.2.

It would seem unusual that Firefox 10 continues running for 2 minutes after shutdown* maybe that is a problem that needs investigating if t happens on your machine in Firefox 10 but not Firefox 3.6.

Loading speed is influenced by the add-ons that are in use. Recent versions of firefox have an option to load tabs when they are needed rather than immediately, and that should speed up loading of Firefox 10 compared with 3.6.
Firefox is not perfect but developers are collecting live data; from real users, about Firefox hangs and Firefox startup times whilst working to improve matters.

*There is a known bug, that is being fixed at present that causes multiple instances of plugincontainer.exe to open when you clear cookies/history if that is what you are seeing hopefully it will be fixed soon (Bug633427) but I think the bug is also present on Firefox 3.6 anyway.

Which security software (firewall, anti-virus) do you have?

A possible cause is security software (firewall, anti-virus software) 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

I use Malwarebytes and Zone Alarm. Both are in place all the time. The only change is Firefox.

So why do older versions of Firefox work fine and newer version don't?

There are two suggestions already mentioned that could explain some of the effects

1. security software
   • as already asked do you need to check and revise security settings, including those of the Zone Alarm firewall.
2. plugin container bug
   • is the disk activity at least partly due to multiple copies of plugin container running ?
     (have you tried to check for this)
     if so maybe this is because firefox 10 has been set to clear history on closing, and firefox 3.6 has not