I may add that the Java console logs:
AppletRelaunch due to health"
before attempting to create new JVMs. However, it gives no further reason and there is more than sufficient memory allocated per vm-args to host all applets within one JVM.
I am particularly puzzled because that used to happen in early version of the next generation plugin but was sort of solved for later versions. Now the problem is re-emerging and with no solution I can see. Sad. Esp. as this is a rather large application.