This week's book giveaway is in the OCAJP 8 forum. We're giving away four copies of OCA Java SE 8 Programmer I Study Guide and have Edward Finegan & Robert Liguori on-line! See this thread for details.
Which version of Maven are you using? Is your project a multi-module project? I ask because we ran into a similar issue in multi-module projects with Maven 3.0.3; when we moved to 3.0.4 to problem went away.