In march 2011 Facebook asked to switch asap from static FMBL to iframes.
Static FBML isn’t working as it used to be and it isn’t allowed anymore to create new tabs through it. Customization of fan pages is a little more difficult now.
Here’s a tutorial about creating custom tabs on your Facebook page with iframes. There’s plenty of it. Really!
There’s much more to do:
- You can use an app to customize your fan page, such as TabPress.
- You can replace your social plugins with XFBML.
- You can explore all your options in order to optimize your page.
Enjoy!