EndNote Smart Groups not working

I created a smart group in EndNote x4 with the following conditions: 

Reference Type is Conference Presentations  - and-

Label is Poster

My intent is to capture all posters presented at conferences. I know I have at least one reference that meets this criteria but the smart group is empty of any references. Any ideas on why this smart group is not working? 

By the way, I have tried changing the criteria from “is” a conference presentation to “contains” conference presentation. I have also done the same for the label field but there are still no records in this group.