Technorati have finally fixed a bug that was preventing some blogs from getting their posts properly indexed on Technorati.
I've posted before that it's best, if you want to get your posts fully indexed on Technorati, to set your blog to output a FULL feed, and noted that Technorati only picks up tags from posts that are on your main blog page (i.e. are displayed in your feed), not post pages or item pages which are no longer shown on your front page.
It seems from a recent post by Kevin Marks of Technorati that not only should the feed whose URL you provide to Technorati be a full feed, but ideally it should be an Atom feed (which Blogger does output). (See this post on how to set autodiscovery for your Blogger feed so search engines will detect the right URL.) UPDATE: plus, Technorati has problems with Feedburner feeds. Aargh.
Technorati's spider will cross check your feed against your main blog page so that if you only put out a summary feed, it will still get the full text from your front page - but unfortunately, until recently it had trouble with blogs whose URLs started with "www" for the feed but not for the main page (or presumably vice versa) (e.g. see this post). And it wasn't fully indexing posts from those kinds of blogs, as Kevin explained. Fortunately, he says they've now fixed that bug.
However, while new posts from such "dual URL" blogs should be indexed properly, "old" posts which never got indexed before still won't be as Technorati (unlike Google) won't index posts off the main page (the last I heard from them) - unless possibly you try getting all those posts onto your main page temporarily (see this post), but even so it may not work for tags if they suffer an indexing glitch during the attempt to crawl your page (see this post!).