I've noticed that there isn't an option to pin threads sometimes. Also, the edit option is frequently missing. This didn't used to be the case. There seem to be other things missing as well—such as the link that lets you make a forum read only or not when doing this from a forum rather than a thread.
When viewing the following thread, the only option I get is 'Permalink':
http://n2.nabble.com/Links-td793582.html#a793582The only items under 'more' are 'Print post' and 'Permalink'.
I use Firefox 3.0 on Linux (Hardy Heron), if that helps at all.
Also, the delete thread feature seems to be missing—I don't know if that is purposeful or not, but that and the edit feature are quite useful for my pinned threads in my read only forums.