If a module is compiled with Java 1.5+ and installed into a Dashboard that is being run under Java 1.4, the module causes the Dashboard to crash when any of its classes are invoked.
Starting with version 4.0 of the NetBeans platform (we are currently using NetBeans 3.6 as of Dashboard 6.0), there is a manifest attribute that allows a module to declare what version of Java it requires. Since we don't have this ability in NetBeans 3.6, we may need to invent it. Or perhaps we can get the code fragments from NB 4.0 and incorporate them.