there are 2 types of show region behaviors. the native Dreamweaver one, and the WA one.
to show a region based on whether a recordset is empty or not, use the Native Dreamweaver one.
on the server behaviors panel, click the plus button and select Show region -> Show If Recordset is not empty. Select the recordset to use from the select list. you don't need to set > 0, you just need to select the recordset to use.