Safari 3.2.1 Sudden Slowdown

Question

I am having similar problems to other posters here, sometimes taking 20 seconds to load a secure page from a site like ups.com. I am running OS X 10.4.11 and Safari 3.2.1. I followed Klaus1's steps; it has not improved. I also called my broadband provider Verizon FIOS and got their DNS server numbers and plugged them in. No change. Downloaded Apple Broadband Tuner, no change. This was not an issue up until about a month ago, seems like after the last security update, all of this started happening.
We replaced the router but I am confident that is not the issue, speed is 2512.3 kbps.
Plugged in my other OS 10.5.6 and Safari 3.2.1, not any better. So I am stumped. Thanks to all for their continuing help...

Answer 1

Copied below are the procedures I followed as outlined by Klaus1:
The following usually works on both Tiger and Leopard:
(First, if yours is an Intel Mac, check that Safari is not running in Rosetta, which is enough to slow it to a crawl.)
Adding DNS codes to your Network Settings, should gives good results in terms of speed-up:
Open System Preferences/Network. Double click on your connection type, or select it in the drop-down menu. Click on TCP/IP and in the box marked 'DNS Servers' enter the following two numbers:
208.67.222.222
208.67.220.220
(An explanation of why that is both safe and a good idea can be read here: http://www.labnol.org/internet/tools/opendsn-what-is-opendns-why-required-2/2587 / )
Whilst in System Preferences/Network you should also turn off 'IPv6' in your preference pane, as otherwise you may not get the full speed benefit (the DNS resolver will default to making SRV queries). If you want to know what IPv6 is:
This is Apple's guidance on iPv6:
http://docs.info.apple.com/article.html?path=Mac/10.5/en/8708.html
Click on Apply Now and close the window.
Restart Safari, and repair permissions.
If that didn't do it, then try this as well:
Empty Safari's cache (from the Safari menu), then close Safari.
Go to Home/Library/Safari and delete the following files:
form values
download.plist
Then go to Home/Library/Preferences and delete
com.apple.Safari.plist
Repair permissions (in Disk Utility).
Start up Safari again, and things should have improved.