Are you up to date?
Have you checked what version of Joomla you are running lately? The current version is 1.5.15
Like any software it is good practice to ensure you are running the latest version to ensure code is up to date, and that the latest security fixes are applied to your website.
Joomla updates are easy to apply, and are available here.
If you are not sure if you are current, then drop us an email and will we check for you.