[link|http://bugzilla.mozilla.org/show_bug.cgi?id=123662|This Bug] in W2K, from bugzilla, showing [link|http://bugzilla.mozilla.org/attachment.cgi?id=67993&action=view|this jpeg] shows the message.
[link|http://bugzilla.mozilla.org/show_bug.cgi?id=141831|This one] is a duplicate of the first, but for MacOS 9.x.
[link|http://bugzilla.mozilla.org/show_bug.cgi?id=155973|Another Duplicate] apparently for ALL OSes involved.
[link|http://bugzilla.mozilla.org/show_bug.cgi?id=167525|Another with Patch] but for a future build.
[link|http://bugzilla.mozilla.org/show_bug.cgi?id=179208|Duplicate for MacOS X], but still there none the less
[link|http://bugzilla.mozilla.org/show_bug.cgi?id=183008|Here is the last] I found.
Evidently these ALL have to do with the "Networking:Cache or HTTP" end on the browser. Probably all caching problems. I have turned my Memory cache to 10MB and disk cache to zero. I use Squid instead. Times right about the time I stopped really having this problem myself, ~2 weeks before 1.2.1 was installed.