I am getting a walkback on this code, with a valid vat:

EventualProcess class>>#newOnVat: vat
	^ super new
		suspendedContext: [
			vat processSends.
			Processor terminateActive] asContext;
		 priority: Processor userSchedulingPriority;
		 eventualName: 'vat thread';
		 vat: vat;
		 yourself

once it has been resumed.  The exception is 
UndefinedObject(Object)>>doesNotUnderstand: #processSends.  Somehow the vat 
variable inside the Closure/MethodContext has become nil.    Anyone know 
about this stuff?

Many thanks,
Rob