Firefox 17 ESR and SeaMonkey 2.29a1. Prior to NoScript 2.6.8.21rc1, it was necessary only to mouse off the menu in order to close it.
Now, it requires an actual mouse click off of it to get it to close.
Downgrading to 2.6.8.20rc3 fixes that.
(SeaMonkey 2.26 not affected.)
EDIT This only applies to the toolbar button. The statusbar icon still works fine.
Regression: sticky menu requires a click to close
Regression: sticky menu requires a click to close
*Always* check the changelogs BEFORE updating that important software!
Mozilla/5.0 (X11; Linux i686; rv:32.0) Gecko/20100101 Firefox/32.0 SeaMonkey/2.29a1
Re: Regression: sticky menu requires a click to close
Fixed in 2.6.8.23rc1, thank you! 
*Always* check the changelogs BEFORE updating that important software!
Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20100101 Firefox/17.0