Also, it looks like it would be a good idea to change the administrator's user name from the default--no need to make it easier for an attacker to get in.
It would also be good to use stronger passwords than you are now:
http://www.blogherald.com/
And: you should periodically create and download backups of the various blogs that you have. (If you want to be safe, burn them to CD or DVD or put them on USB drive, etc. in case your computer has problems of its own.)
More info: http://lorelle.wordpress.com/
