The BO will only show the error provider next to controls that are bound to the business object. So, if you have 2 business objects using the SharedDataTableKey, if all of the controls are bound to one, and you call CheckRulesOnRow() on the other, then none of the error provider icons will show. When you're stepping through the CheckRulesOnRow() method, check the value of the Me.BoundControls.Count property within the watch window. If it's 0, then all of the controls are bound to the other business object.As for the red InfoBox not appearing, I think that is an issue that was introduced in a previous version and is slated to be fixed for 1.6.1