This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
Right-click the project name, get properties, then go through it (I think it might be build path) until you find the Java version your project is using. It might not be the same as what you are using for everything else.