In a previous paper (Loizou, F. 2011. How Cypriot primary school teachers promote their professional development through reflective practice. "Education 3-13" 39, no. 3: 233--247.) I explored the concept of theories-in-use within a qualitative research study in order to analyse the role of reflection in bringing about change in the practice of 18 Cypriot primary school teachers. In this article, I build on the findings of this study in order to explore further why reflection onpractice which remains unexamined through professional exchange can have alimiting effect on professional development. In particular, I aim to examine which devices can develop in the unconscious in order to protect unsound theories-in-use and reinforce discrepancies between actions and espoused beliefs. Furthermore, I discuss why these devices block awareness of the need to change. Finally, I make hypotheses about when the above devices could have been developed in the Cypriot teachers' unconscious. The article concludes with suggestions about how the activation of the above devices can be limited or prevented.