The function SetPTabular(TokArr value, TokArr prob, TokArr parentValue) is sensitive to the order in which nodes (and/or possibly arcs) are added to the network. The resulting behavior is that SetPTabular can result in conditional probabilities for a node different than what is specified by the user (the values get written to the wrong cells of the node's CPT).
The attached code provides a simple example of the bug in action. Three parent nodes and one child node are created. The appropriate arcs are created. A series of SetPTabular calls are executed and the resulting GetPTabular call does not correspond to what was specified.
source for recreating the bug