--- a/flys-artifacts/src/main/java/de/intevation/flys/artifacts/datacage/Datacage.java	Wed Sep 21 12:55:36 2011 +0000
+++ b/flys-artifacts/src/main/java/de/intevation/flys/artifacts/datacage/Datacage.java	Wed Sep 21 13:01:25 2011 +0000
@@ -488,8 +488,13 @@
     ) {
         log.debug("createdArtifact");
 
+        if (artifact == null) {
+            log.warn("artifact to create is null");
+            return;
+        }
+
         if (!(artifact instanceof FLYSArtifact)) {
-            log.warn("need FLYSArtifact here");
+            log.warn("need FLYSArtifact here (have " + artifact.getClass() + ")");
             return;
         }
 
@@ -536,7 +541,7 @@
     ) {
         log.debug("storedArtifact");
         if (!(artifact instanceof FLYSArtifact)) {
-            log.warn("need FLYSArtifact here");
+            log.warn("need FLYSArtifact here but have a " + artifact.getClass());
             return;
         }