I have installed the 2.1.2 version of the Zotero. Two of the problems mentioned in this thread are fixed (date issues and case-insensitive sort), but the sorting of Norwegian characters is still wrong. The CSL editor sorting works, but not the word processor plug-ins.
Now I've upgraded to version 2.1.4 and the sort order of Norwegian characters (and other Scandinavian characters like Ö) is still wrong. Will there be a fix for this soon? (I'm using Firefox 3.6.16, by the way.)
I've been tied down today with work on the multilingual Zotero version (where I made a stupid mistake in the code a few weeks ago, which came back to bite yesterday). But I think I know what's breaking the sort for these characters. If you don't hear anything further, assume that a fix will be forthcoming in the next release of Zotero (2.1.5).
(I'm using Firefox 3.6.16, by the way.)