SABnzbd settings will now dynamically get the categories available from SABnzbd when the category drop-box gets focus, it will use values on the page so there is no need to save your settings first.

NzbDrone.Core/Model/SabnzbdCategoryModel.cs

@@ -0,0 +1,12 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+namespace NzbDrone.Core.Model
+{
+    public class SabnzbdCategoryModel
+    {
+        public List<string> categories { get; set; }
+    }
+}