AVC Low Level Procedure fires but no value inferred.

I have a simple AVC model.

Parent = CAR

Sub-Items are CAR_DOOR x 5   = each have a class with an instance cstic.

A classic selection condition fires and selects the CAR_DOOR component.

A classic procedure assigns a different instance number for each CAR_DOOR component..

In the trace it shows the procedure 'fulfilled"- but the instance cstic value is not inferred. (see attachment)

Has anyone else encountered this behavior in AVC ?

BR Steve