RobertJ wrote:After reading this
https://bugzilla.mozilla.org/show_bug.cgi?id=633427
it appears that even if plug-ins are disabled the process spawning is triggered by removing LSO cookies that occur in plug-ins like flash. Apparently FF opens the plug-ins to clear the cookies. Not sure why I'm not seeing this on Mac. You might go to the above link and add what you are seeing on FF4 on XP.
Just before reading your post I discovered that clearing the history (Tools -> Clear Recent History) spawns the multiple plugin-container.exe processes. I read a similar report over at bugzilla.mozilla.org and tested it and indeed it spawned a bunch of instances.
I think that's what is doing it. I frequently clear my history. Firefox never behaved like this with 3.6.x. Later tonight I'll do a little web surfing and not clear my history for a while and see what happens.
Thanks for your help.