i5-750, 4GB ram.
Note that this is the same computer, Profile, browser where the issue was not apparent the other day,
http://forums.informaction.com/viewtopi ... 078#p24078. Also reverting back to NoScript 1.9.x alleviates the problem.
High CPU (25% = 1 core), relatively long duration.
Initially opened from Session Restore.
Then things settled down. Then I opened, closed NoScript Options a few times, waiting a bit between open/close.
Imagine I'll see similar results on an E4300, 2GB ram, & a newly opened browser, clean Profile, about:blank, & only NoScript installed. (The video above was from this computer. Don't remember what else may have been open at the time, though it was with clean Profile & only NoScript.)
(View Image, for full size)

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 6.1; en-US; rv:1.9.1.17pre) Gecko/20101216 SeaMonkey/2.0.12pre