WordPress is a great tool, but make sure you keep it up to date to avoid security vulnerabilities. I have fixed a number of outdated and hacked versions of WordPress over the past few years which could have easily been taken care of by keeping up to date with WordPress updates a few times a year. If you are using WordPress 2.5+ it is really easy to be notified when a plugin or WordPress has a new version available when you log in.
If you do not want to go through the process of using svn or ftp to update your files, WordPress even gives you the option to automatically update.
If you suspect you were hacked, feel free to contact us and we will update and clean your site.