SJK Here, the "Kill Gif Animation" option is dimmed-out under the General tab in the SafariStand Setting window of SS 3.1L161; you can read the text but can't (dis|en)able it. Not sure about earlier versions because I was using PithHelmet's "Animate Images: Once" option (ideal for me) before that (and machete scripts, alas) broke with Safari 3. I vaguely remember reading it's similar with Saft, too. The Glims feature list doesn't mention anything about support animation blocking, which I'd think it would if it was possible.
That's some background behind my earlier "tough issue to resolve" remark.
(Version 4.0L166)