The programming language Arden Syntax is especially adapted to the needs of computer-based clinical decision support. Recently, an extension of Arden Syntax, named Fuzzy Arden Syntax, was proposed by the authors. Fuzzy Arden Syntax is a conservative extension of Arden Syntax and offers special functionality to process gradual information. The background is the observation that in medicine we frequently deal with statements which are neither clearly false nor clearly true but hold to some intermediate degree. In this paper, we demonstrate under which circumstances a Medical Logic Module (a program unit written in Arden Syntax) may show unintended behavior and how the situation can easily be improved by means of the possibilities offered by Fuzzy Arden Syntax. To this end, an example from the domain of nosocomial infection control is discussed in detail.