Index: /trunk/glueforge/templates/psdb/printmetadataraw.tt
===================================================================
--- /trunk/glueforge/templates/psdb/printmetadataraw.tt	(revision 10430)
+++ /trunk/glueforge/templates/psdb/printmetadataraw.tt	(revision 10431)
@@ -39,6 +39,10 @@
             METADATAITEM_STRIFY_CASE(PS_DATA_F64, "%f", F64);
             case PS_DATA_STRING:
-                psStringSubstitute(str, " ", "_");
-                psStringAppend(&str, "%s", item->data.str);
+                if (item->data.str) {
+                    psString tmpStr = psStringCopy(item->data.str);
+                    psStringSubstitute(tmpStr, "_", " ");
+                    psStringAppend(&str, "%s", tmpStr);
+                    psFree(tmpStr);
+                }
                 break;
             case PS_DATA_BOOL: