For some reason none of my posts to the cocoa-dev list are getting through so here's question for the forum. I have a NSTableview with a datasource consisting of an NSArray of dictionaries. One column in my table has an NSPopupbuttonCell. The content and contentValues are bound to a Core Data "Account" object. I use a "name" property as my contentValue. I'm having trouble changing the popup button. I know in my datasource I get an index of the selected object and in my setObjectValue datasource method I set the key in the dictionary with this new NSNumber intValue. However, in operation when I change the popupbutton it very quickly changes back to the first object in the list (index 0). Clearly I'm missing something or have set something wrongly in IB.