Hi folks. After a couple of hours of trying to find a problem, I finally come to the cause: using super initialize is not always good. When I implement #initialize, I ALWAYS do "super initialize" in the first line of such method. Today, I found a problem while doing this in class side #initialize. I have a particular class and I did: MyClass class >> initialize super initialize. "My own specific code to run" But when sending MyClass initialize, I discovered that the "super initialize" did something I wasnt aware: Behavior >> initialize "moved here from the class side's #new" super initialize. superclass := Object. "no longer sending any messages, some of them crash the VM" methodDict := self emptyMethodDictionary. format := Object format in my case MyClass has subclass from ProtoObject, not Object. And of course, I got an empy method dictionary...etc. So...I just wanted to share my problem to avoid other's one. Cheers Mariano