Do you store any of the services or objects outside of the service projects? This way the classes couldn't be unloaded and you'd see unexpected results with stale old class code in random locations.

If you stick with @Reference and forget about those objects after you've used them in a request, nothing bad should happen. But if you hold them any longer (including the model objects), you might see weird behavior - especially if you're calling methods on them while two of the class's definitions are around.

Hi Olaf. Thanks for your time.

I mainly do simple stuff like: 

1. Create a ResourceCommand class
2. Declare @Reference to MyServiceBuilder in the resource command. eg:
   1. @Reference
   2. private volatile MyLocalService myLocalService
3. Call a method
   1. myLocalService.dosomething();

Only thing out of the ordinary is that I have declared a class inside the servicebuilder project that i use in the other projects. eg:

1. CustomClassDefinedInServiceBuilder something = myLocalService.doSomething();

Don't know if this could cause the problem. I also get errors for things that are not related to that custom class. I also get a nosuchmethod exception on myLocalService.doSomething() if I change the signature of doSomething() for example. 

Anyway this is not a blocking problem. Just takes a takes a bit more time waiting for the server to restart. 

Thanks again.