Molasses slow after security & safari updates

Question

After 2 days of my own trial and error, I checked the boards and discovered I am far from alone in these problems. I tried entering the DNS addresses suggested by BDAqua but that has helped only minimally (that may be of little surprise, though, because I connect to the internet with a USB wireless Novotel modem, not a router). Nothing else about my system has changed. As it happens, because of suddenly stuttering video feeds a few days ago -- which led me to do this "optimizing" (or so I'd hoped!) -- I HAD repaired Disk Permissions and Verified Disc, as well as performing my regular system maintenance with ONYX both before & after but it wasn't until I began reading all the posts by all the frustrated people that I had ever seen in print that those operations were considered basic protocol when installing updates of any sort. I do backup everything compulsively (file backup though, not clone) so haven't lost anything data-wise but would prefer to avoid having to do a clean OS reinstall, then reinstall all of my many huge professional apps, and then reconfigure all the prefs and customizations of everything to get them back "just so" exactly as I like. Of course, I've rebooted after each fix step and also shut down completely several times to let my MBP remain off for many hours. I guess I'm a little luckier than some other posters because, aside from my browsers (Safari, which I favor, and Firefox) & general Finder operations, no other applications seem to be affected.
The symptoms are that new windows/tabs load at 15bps -- sometimes the loading indicator spinning on endlessly without any items appearing on page -- and downloading occurs at same ridiculous transfer rate although Internet Connect confirms that I'm connected at the usual 1843200bps. This happens on the simplest of pages (each Apple Discussion page takes a full 5 minutes to load, when they do actually load completely). The spinning rainbow pinwheel-o-doom occurs when switching between open windows/tabs in browser or Finder or when moving from Finder to Browser and back again.
Any ideas?
As an aside, in response to several other threads, I herewith offer my Two Cents: After many years of problems happening after applying various updates, I've become wary (not to mention, jaded) and thus only perform local system maintenance with trusted Tools and Utilities, avoiding software updates, as long as my system is running successfully. When I do encounter other problems, and Updates have recently been released that promise to fix glitches and increase overall stability, I use System Updater, to avoid possibly selecting an incorrect patch version. Furthermore, I totally agree with the frustrations expressed in one related post (http://discussions.apple.com/thread.jspa?messageID=8071700&#8071700), and was heartened to find several supporters of the originator at the end of the very lengthy thread. I agree that if certain basics are germane to the success of the Update process each and every time, that the updaters ought to have fix/verify built right in. Many inexperienced home users blindly agree to every update Apple or installed third-party developer suggests, they also tend to be the people who feel too intimidated to search these discussions, if they even know they exist at all. I love Apple dearly and agree that Tiger is an extremely stable OS but all the OSX versions have been much more complex to learn to troubleshoot through day-to-day use than the OS9 environments. Gone are the days when the average user felt secure trashing specific Preference files or replacing a single Extension with a clean version -- and gone are the days when one could select from three OS install options, one of which performed a less invasive basic Apple-OS-item-only install. Given that OSX versions just get increasingly bulky and confusing to the uninitiated, I believe it does fall on Apple to build into update/patch scripts ALL the required steps to ensure a fully automated process, or to at least provide interactive "steps" where a user can choose "OK" (as in, I've already done this) or "Open For Me" as in the Help scripts, prior to any patch/update script running itself.

Answer 1

Thanks, BDAqua! Glad you're here for us!
I do have my Onyx configured to dump Browser Caches, along with those for Fonts, System, and Kernel. Also, it is my normal procedure, when I've been surfing for hours, visiting many sites and/or streaming many videos, to use the Safari menu to periodically clear the Browser Cache myself (I find it prevents Safari from getting sluggish) as well as to clean out my cookies often. If you recommend AppleJack over Onyx, however, I will certainly give that a try. Any other suggestions?
I NEVER used to get "buffering video" issues -- not since I migrated from my old cpu and dial-up modem, anyway -- but since the Security Update and Safari Upgrade, I get between 90-200 seconds of uninterrupted video before having to wait an equal or greater amount of time for it to catch up. This is improved only a small bit by letting the whole stream load before playing and it's not only excruciating but upsetting as well since this was NOT the case before I implemented those updates. I can no longer run one video while allowing another to queue up in a second tab (I'm accessing only trusted video sites such as Netflix, YouTube, and MegaVideo). I can no longer run searches in one window while doing anything active in another window. I am accustomed to multi-tasking and this sudden lack of internet performance is a huge hinderance. I have 2gigs RAM and since this happened have been running no other apps besides a browser, although I used to be able to have many windows/tabs open plus a Mail Client or graphics app to boot without any issues. I suppose that, since the problem seems to stem from the Security Update, not the new Safari, that reinstalling a clean version of Safari 3.2.1 wouldn't help? The only way to clear the Security Update out, if there is no successful fix localized to settings and preferences, is to completely reinstall my system and all my software and utilities...