Two experiments are reported that test whether the modulation of exogenous cuing effects by the presence of a distractor at the location opposite the target (altering the time course of cueing effects, Lupiáñez et al., 1999, 2001) is due to the fast reorienting of attention or to a set for preventing the integration of the cue and the target within a single event representation. A Spatial Stroop task was used to explore whether the long lasting facilitation effect usually found in this task, as well as the typical reduction of Spatial Stroop interference on cued trials (Funes et al., 2003, 2005) is prevented by the presence of distractors. In Experiment 1, the distractor produced a shift towards more negative cuing effects even at the shortest 100 ms SOA, and eliminated the Spatial Stroop by Cueing interaction. In Experiment 2, a larger range of SOAs was introduced, demonstrating further that the negative shift of cueing effects found in Experiment 1 affected all levels of SOA equally. This pattern of results is explained in terms of the event segregation hypothesis.