=== modified file 'dhis-2/dhis-web/dhis-web-api/src/main/java/org/hisp/dhis/api/controller/DataValueController.java'
--- dhis-2/dhis-web/dhis-web-api/src/main/java/org/hisp/dhis/api/controller/DataValueController.java	2013-12-19 23:00:15 +0000
+++ dhis-2/dhis-web/dhis-web-api/src/main/java/org/hisp/dhis/api/controller/DataValueController.java	2013-12-19 23:08:40 +0000
@@ -163,7 +163,7 @@
             {
                 DataElementCategoryOption categoryOption = categoryService.getDataElementCategoryOption( id );
                 
-                if ( categoryOption != null )
+                if ( categoryOption == null )
                 {
                     ContextUtils.conflictResponse( response, "Illegal category option identifier: " + id );
                     return;