Bidirectional user interfaces serve more than half a billion users worldwide. Despite increasing diversity-driven approaches to interface development, bidirectional interfaces still use UI items' directionality inconsistently and incorrectly. Designers should pay special attention to UI items containing ambiguous information that can be processed both from right to left and from left to right by bidirectional users. Such items are susceptible to ineffective use. This paper reports preliminary results from a study with 1705 Arabic and Hebrew users. We investigated the directional interpretation of 16 UI items, empirically demonstrating the ambiguity problem in bidirectional interfaces and the potential influence of UI factors on how users interpret the items' directionality. While the study indicates that preventing all interpretation errors is unlikely, a large portion of those errors can be addressed by proper design.