Firefox 2 slowing down win-98 on some sites - why?

[Nomen]

I've been noticing that Firefox 2.0.0.20, when viewing more websites lately, is doing something in the background that is dragging down the whole system. This doesn't seem to be related to script timeouts.

Is there any way to know what FF2 is doing during these periods of extreme unresponsiveness?

Edit: Upon posting the above message, I got this:

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An error occured with the SQL server:

mySQL query error: SELECT cs_value, cs_updated FROM x_utf_ibf_cache_store WHERE cs_key='mail_processing'

This is not a problem with the IPS Community Suite but rather with your SQL server. Please contact your host and copy the message shown above.

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With no indication that msfn server had accepted the post. I'm using Netscape Navigator 9.0.0.6 to post this.

Edited September 25, 2014 by Nomen

[jumper]

Content coming from multiple servers always seem to slow FF2 down. If some of the site assets are on a slow server (like a public file host), try blocking that server or disabling the loading of images entirely. If you block enough of a page, eventually the rest will load quickly.

Also make sure any plug-ins that might be scanning every page are disabling (while testing). Even ABP and ABElements could be the culprit.

[Nomen]

I should have said that I make aggressive use of my hosts file, where I periodically check my router's outbound logs to see what domains my computer is trying to contact. I block all click-tracking, web-metrics, advertising, fecebook and twitter access that I can identify through host file entries.

I also run Abyss Web Server, which serves up any HTTPS files locally as a result of redirection to 127.0.0.1. I've gone out and obtained these files manually (the vast majority being .js files, about 77 of them so far, rum.js, various versions of jquery.js, etc). I expand the js files and inspect them to see if they themselves are trying to access hosts that I don't want them to, and modify the URL as necessary to prevent the access.