Aside from the unrelated tweetbacks and the date problems, here's a 3rd bug I've noticed still appearing in v1.4.3: MySQL connection timeouts.
Here's what it looks like in my error_log:
[Sun Jan 18 19:53:37 2009] [error] [client xxx.xxx.xxx.xxx] WordPress database error Lost connection to MySQL server during query for query SELECT meta_key FROM wp_1_postmeta WHERE meta_key = 'tweetbackscheck' AND post_id = 11 made by update_post_meta
I've turned off Tweetbacks for now.
Any ideas, Joost?