If you are running Wordpress 2.1.1, then there is some bad news. According to announcement on Wordpress blog, a cracker managed to add some security exploit files in archive of Wordpress 2.1.1.
Wordpress guys have fixed this issue in version 2.1.2.
Please update your Wordpress ASAP.

04-Mar-2007 at 10:28 am
Roger that Deep! Learn’t this couple of days back from Digg. Amusing as how ppl crack into secured servers. Anyways just passed to tell the Theme Rocks..!
Cheers,
Vinay
05-Mar-2007 at 12:13 pm
Hmm this vulnerability is only for those who downloaded the wordpress installation file in the last week.