In the Dusunic languages of Sabah, Malaysia, there is an alternation in transitive clauses between verbs with the prefixes po- and poN-. In a series of papers beginning in 1996, Paul Kroeger has claimed that in Kimaragang that alternation marks what he terms undergoer affectedness, being conditioned by the thematic role of the undergoer in the transitive clause. Though I do not deny that the undergoer effects Kroeger identifies are real, I argue in this paper that they are epiphenomenal. In the analysis I present, based on both Kroeger's Kimaragang evidence and on data from Bundu Tuhan Dusan, Dusunic po- and poN- in transitive clauses are not undergoer agreement markers of any sort. I argue that poN- marks the profiling of an ACT phase in event structure, a function in all probability inherited from some pre-Dusunic period. The particular function of po- that gives rise to Kroeger's undergoer alternations is as a substitute for conveyance voice, a function that is probably a Dusunic innovation.