Memory tasks combining storage and distracting activities performed at either encoding or retrieval have provided divergent results pointing towards accounts of forgetting in terms of either temporal decay or event-based interference respectively. This study sheds light on the possible sources of such a divergence. Methodological issues were explored in a first series of experiments by introducing at retrieval computerpaced distracting tasks that involved articulatory suppression, attentional demand, or both. The second series of experiments induced differences in the nature of memory traces by increasing the encoding time. Although the introduction of computer-paced distracting tasks allowed for a strict control of temporal parameters, the first series of experiments replicated the effects usually attributed to event-based interference. However, deeper encoding abolished these effects while timerelated effects remained unchanged. These findings suggest that the interplay between temporal factors and event-based interference in forgetting at short term depends on the nature of memory traces.