Usually i run a junit test using adb shell am instrument -w com.android.contacts.tests/android.test.InstrumentationTestRunner. And it actually works, it will run al
I guess you are trying to debug your tests using Eclipse. If this is the case you can just select you test project, right click, Debug As... -> Android JUNit test and the execution will stop at the breakpoints you set in your tests or in your code.