If I attempt to instantiate an [mxj] with one of my classes, Max hangs forever. If, however, I first instantiate one of the example Java classes (e.g. [mxj echo]), and then instantiate one of mine, everything runs perfectly.
I've tried shuffling things in my Java project around, exporting a Jar instead of letting Max use the class files, tinkering with the settings in the max.java.config.txt file, moving my one non-max.jar dependency (log4j.jar) to different locations. No dice.
Finally, if I instantiate any of my Java classes in Max 5, everything works perfect.