Invalid source release: 1.7

This error is driving me mad. Upon opening Intelli J 11 today I started my usual work and eveything was fine. Then the make starting throwing this error "Invalid source release: 1.7" when I haven't changed any of the settings I've spent an hour now trying to change any settings referring to the compiler version and can't seem to fix it. My sdk version is 1.7, so is the language level and my JAVA_HOME points to the the Java 7 JDK. I have no extra options in my compiler or maven runner.