I'm using Maven with 'Eclipse Kepler JavaEE'. I have something like this in 'maven-compiler-plugin' :
<configuration>
<source>1.7</source>
<target>1.7</target>
</configuration>
Each time I'm changing somethin in 'pom.xml', eclipse forces me to perform 'Maven -> Update Project' and than project settings are changed to use JRE instead JDK and some maven builds are stopping to work.
The only solution I found to solve it is to set How I can set eclipse/m2e to use JDK is to define a path in maven-compiler-plugin. It is not good solution, since it is working only for my computer will fail for other.
I think there are some maven or m2e definitions saying "use jdk and not jre".
In Eclipse, open Window | Preferences | Java | Installed JREs, make sure there's a JDK (and not just a JRE) for Java 1.7, then go to the submenu Execution Environments and mark this JDK as compatible with JavaSE-1.7.
After that, Maven | Update Project should work as desired.