I've tweaked the random page selection to drop pages from the queue as they are picked, then refill the queue once it's empty.
Compared to the previous behavior, this should: a) prevent duplicate selections for people who keep sitting there and clicking the damn button over and over b) avoid the "random only shows the main page" bug on smaller, newer wikis that haven't had enough traffic to happen to trip the random queue refilling.
-- brion vibber (brion @ pobox.com)