No idea,
But a suggestion, you should upgrade your version of m2e from 0.12 to 1.0+ m2e-scala 0.3.1 is made to work with this version of m2e.
How to do run test ?
* run test on a directory/package
* run test via maven menu
when it doesn't run java test, can you check if the .class of the java test exist under target/test-classes or target/classes
same question but when java test run.
/davidB