The Store Model of Halpern-Meyer-Trakhtenbrot is shown—after suitable repair—to be a fully abstract model for a limited fragment of ALGOL in which procedures do not take procedure parameters. A simple counter-example involving a parameter of program type shows that the model is not fully abstract in general. Previous proof systems for reasoning about procedures are typically sound for the HMT store model, so it follows that theorems about the counter-example are independent of such proof systems. Based on a generalization of standard cpo based models to structures called locally complete partial orders (lcpo's), improved models and stronger proof rules are developed to handle such examples.