Usability-evaluations is commonly used to identify the usability-problems of a software system. However, it is a known problem that novices of usability-inspections report fewer usability-problems than evaluators with expertises within the topic of usabilityevaluations. However, little to no research investigates why novices report less usability-problems. In this article, we investigate this problem by having three groups containing 5 evaluators with one shared area of expertise evaluating a software system. These groups consisted of usability experts, system experts, as well as experts on the field of which a system is used. Results showed that out of the 326 usability-problems occurred during usability-inspections 126 was not reported. Furthermore we found 16 specific reasons why evaluators fail to report usability-problems that occurred during a usability-inspection.