(Reverted to) NoScript 1.9.3.3, SeaMonkey 1.1.17, AMD.
Pretty much went through (today's) history & opened EVERYTHING back up. Mem Usage going up & up. CPU through the roof. All to be expected.
http://i40.tinypic.com/5yw0fb.jpg
Took quite a while before CPU finally dropped & I could start doing things again

.
http://i42.tinypic.com/2mqka48.jpg
Right now I sitting I'm sitting at 350MB & minimal CPU.
I'll run it for a while & then start closing windows & see what happens.
I've closed a LOT, but still have a LOT open.
Mem Usage has dropped from 350MB to 245MB.
Closing more & now I'm at 200MB. I've got 3 windows/16 tabs open.
Interestingly, as I've now opened some new windows, Mem Usage has actually dropped to 170MB. And as I open more, I've gone back up to 190MB.
... edits (additions) to come ...
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1.19) Gecko/20110420 SeaMonkey/2.0.14 Pinball NoScript FlashGot AdblockPlus
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.22) Gecko/20090605 SeaMonkey/1.1.17