The upgrade to WP 3.3.1 appears to have gone through all right, though I haven't clicked absolutely everything. However, every RSS link returns this error message:
Warning: require_once(/home/user/domain/wp-includes/feed-rss2.php) [function.require-once]: failed to open stream: No such file or directory in /home/user/domain/wp-includes/theme.php on line 1115
Fatal error: require_once() [function.require]: Failed opening required '/home/user/domain/wp-includes/feed-rss2.php' (include_path='.:/usr/local/lib/php:/usr/local/php5/lib/pear') in /home/user/domain/wp-includes/theme.php on line 1115
It's not that I'm desperate to have my RSS feed accessible, but some viewers like them.
By the way, I'm using "themorningafter" theme by WooThemes - the most recent version. Just installed it a week or two ago. And no, it costs a fortune to get support there, so I'm here, in case someone has something helpful to contribute. Thanks.