We study interaction interferences, situations where an unexpected change occurs in an interface immediately before the user performs an action, causing the corresponding input to be misinterpreted by the system. For example, a user tries to select an item in a list, but the list is automatically updated immediately before the click, causing the wrong item to be selected. First, we formally define interaction interferences and discuss their causes from behavioral and system-design perspectives. Then, we report the results of a survey examining users' perceptions of the frequency, frustration, and severity of interaction interferences. We also report a controlled experiment , based on state-of-the-art experimental protocols from neuroscience, that explores the minimum time interval, before clicking, below which participants could not refrain from completing their action. Finally, we discuss our findings and their implications for system design, paving the way for future work.