Unsupported MIME type: text/plain
which is disappointing, since the overall request is typed as application/x.atom+xml. The only text/plain is in the body of the post, and that matches the Nokia lifeblog protocol spec's examples - except that the spec has "a:" prefixes on everything. Hmm.
Anyway, Support query posted to LJ.
I did manage to get posting to flickr working, although that took some hassle - turns out that flickr wants different username/password for mobile accounts....