Loading http://www.w3.org/Math/XSL/pmathml.xsl makes Firefox show an infobar saying "Additional plugins are required to display all the media on this page." This is incorrect; adding plugins would not affect how this XSL stylesheet is displayed! (The root element is in the "http://www.w3.org/1999/XSL/Transform" namespace.)

What build of firefox?

I can reproduce this using the testcase in today's windows trunk build, but not in today's windows 1.8 branch build.

Regression range for this is 2005-11-11 05 - 2005-11-11 13. Checkins: http://bonsai.mozilla.org/cvsquery.cgi?module=PhoenixTinderbox&date=explicit&mindate=2005-11-11+04%3A00&maxdate=2005-11-11+14%3A00

The checkin for bug 309521 sounds likely.

Bug 836415 has now removed the Plugin Finder Service (PFS) from Firefox. As a result, I'm closing all the remaining PFS bugs. If you're getting this bugmail for an ancient PFS bug, the basic summary of the world today is: * NPAPI plugins are a dying technology * PFS was already restricted to assisting with only the 4 most common plugins * Sites commonly provide their own UI for install a required plugin * Mozilla is generally focusing on improving the web platform so that proprietary plugins are not required. (Note that "plugins" are a completely separate from "browser extensions", such at those found on addons.mozilla.org. The latter are not going anywhere, and are not impacted by the removal of PFS.)