It seems like every other week, WordPress releases a new version of their awesome software. That’s a good thing, unless you run multiple websites using WordPress.
If you’re in that boat, upgrading all of your WordPress sites might be a pain in the butt, but it’s extremely important to do so.
The main reason for these “dot releases” (ie; 2.5.1) are security fixes. Which means that when someone finds a way to “hack” your WordPress installation, the new release fixes that.
What’s that mean? Well, if you’re running a version that’s old, there’s probably a group of people out there that’ve found a security hole in it. They can gain access to your account, and cause all sorts of problems for you.
For example, if you’re running WordPress 2.3.2, there’s a very simple “hack” that anyone with the power of Google can do, that can give them complete access to your Admin panel. And well, you know what they do from there, including deleting everything on your blog, that you’ve ever done.
So, be sure to stay up to date. Always update plugins, always update core code. Always.