From my informal testing, it appears that in the login response, mood_50_name (which should be "groggy") is coming back blank intermittently... something like 30% of the time.
I ran this command:
for i in 1 2 3 4 5 6 7 8 9 10; do curl http://www.livejournal.com/interface/flat -i -d "mode=login&hpassword=[mypw]&getmenus=1&getmoods=0&getpickws=1&clientversion=GTK2%2DLogJam%2F4%2E0%2E1&user=evan&ver=1" > $i; sleep 1; done
which is a cut'n'paste from a real client login. It retrieves the results of a login to LJ 10 times, a second apart each, and requests the full mood list each time.
With these results, I run:
grep -A 1 mood_50 *
So are some of the servers corrupted somehow? I retrieved the HTTP headers, too, but they don't include which web slave is handling my requests. I can't think of what else is causing this intermittance. Worse, once a client retrieves the mood list and caches it, if they don't get groggy on their first request they'll never get it at all (because in the future they'll think they already have the full mood list).