Software update just ran to update me from trunk linux 2007040804 to 2007040904, and while it ran, I got Error: [Exception... "'Component does not have requested interface' when calling method: [nsIInterfaceRequestor::getInterface]" nsresult: "0x80004002 (NS_NOINTERFACE)" location: "<unknown>" data: no] 376 times. Recently changed extensions are Firebug 1.04 and FullerScreen 1.0a1, so it may have to do with one of those.

Related to bug 374499?

Certainly the same regression range: "Works" (no error thrown in error console) Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9a3pre) Gecko/2007031504 Minefield/3.0a3pre "Broken" (errors thrown in error console) Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.9a3pre) Gecko/2007031605 Minefield/3.0a3pre http://bonsai.mozilla.org/cvsquery.cgi?treeid=default&module=PhoenixTinderbox&branch=HEAD&branchtype=match&dir=&file=&filetype=match&who=&whotype=match&sortby=Date&hours=2&date=explicit&mindate=2007-03-15+03&maxdate=2007-03-16+06&cvsroot=%2Fcvsroot

Just tested with a new download and a clean profile, still get the errors, so it's not extension related.

Software update and extension update both use badCertHandler, this is the same issue.