If you are a Facebook Page administrator you should know Facebook is set to begin rolling out narrower Page tabs today. The width of the tabs will be reduced from 720 pixels to 520.
The change was announced back in October 2009 but was delayed, so you could prepare for the reduced tab width. I'm guessing many pages still use 760 pixel wide elements, which will look broken once Facebook implements the change.
If your Page contains elements that are over 520 pixels wide, you should reduce them to that width as soon as possible.