Firefox hogging memory

I am running Firefox 2.0, a few plugins, NoScript, Fasterfox, and Adblock, and it really seems to be hogging memory. Earlier I had a few largely text only academic sites open, and my machine was running really slowly, so I looked at the Task Manager and saw that Firefox was hogging well over 200MB of RAM!
I don't seem to have any spyware installed, and neither the plugins that I use nor the webpages I had open are overly chunky, any ideas what might be causing it?

http://kb.mozillazine.org/Reducing_memory_usage_(Firefox)

Give that a try

thanks