diff --git a/webapp/src/edu/cornell/mannlib/vitro/webapp/ontology/update/ABoxUpdater.java b/webapp/src/edu/cornell/mannlib/vitro/webapp/ontology/update/ABoxUpdater.java
index b98ed418e..de39c4cfa 100644
--- a/webapp/src/edu/cornell/mannlib/vitro/webapp/ontology/update/ABoxUpdater.java
+++ b/webapp/src/edu/cornell/mannlib/vitro/webapp/ontology/update/ABoxUpdater.java
@@ -24,7 +24,6 @@ import com.hp.hpl.jena.shared.Lock;
 import com.hp.hpl.jena.vocabulary.OWL;
 import com.hp.hpl.jena.vocabulary.RDF;
 
-import edu.cornell.mannlib.vitro.webapp.dao.VitroVocabulary;
 import edu.cornell.mannlib.vitro.webapp.ontology.update.AtomicOntologyChange.AtomicChangeType;
 
 /**  
@@ -425,14 +424,18 @@ public class ABoxUpdater {
 		while(propItr.hasNext()){
 			AtomicOntologyChange propChangeObj = propItr.next();
 			switch (propChangeObj.getAtomicChangeType()){
-			case ADD: addProperty(propChangeObj);
-			break;
-			case DELETE: deleteProperty(propChangeObj);
-			break;
-			case RENAME: renameProperty(propChangeObj);
-			break;
-			default: logger.logError("unexpected change type indicator: " + propChangeObj.getAtomicChangeType());
-			break;
+			  case ADD: 
+			   addProperty(propChangeObj);
+			   break;
+			case DELETE: 
+			   deleteProperty(propChangeObj);
+			   break;
+			case RENAME: 
+			   renameProperty(propChangeObj);
+			   break;
+			default: 
+			   logger.logError("unexpected change type indicator: " + propChangeObj.getAtomicChangeType());
+			   break;
 		    }		
 		}
 	}
diff --git a/webapp/src/edu/cornell/mannlib/vitro/webapp/reasoner/SimpleReasoner.java b/webapp/src/edu/cornell/mannlib/vitro/webapp/reasoner/SimpleReasoner.java
index 700bf8f4a..ffdcb8ee4 100644
--- a/webapp/src/edu/cornell/mannlib/vitro/webapp/reasoner/SimpleReasoner.java
+++ b/webapp/src/edu/cornell/mannlib/vitro/webapp/reasoner/SimpleReasoner.java
@@ -419,8 +419,10 @@ public class SimpleReasoner extends StatementListener {
 			    
 				if (cls != null) {
 					
-					List<OntClass> parents = (cls.listSuperClasses(false)).toList();		
+					List<OntClass> parents = null;
+					parents = (cls.listSuperClasses(false)).toList();		
 					parents.addAll((cls.listEquivalentClasses()).toList());
+					
 					Iterator<OntClass> parentIt = parents.iterator();
 					
 					while (parentIt.hasNext()) {
@@ -453,7 +455,9 @@ public class SimpleReasoner extends StatementListener {
 				}
 			} else {
 				log.warn("The object of this rdf:type assertion has a null URI: " + stmtString(stmt));
-			}			
+			}		
+		} catch (Exception e) {
+			log.warn("exception while removing abox type assertions: " + e.getMessage());
 		} finally {
 			tboxModel.leaveCriticalSection();
 		}
@@ -530,6 +534,9 @@ public class SimpleReasoner extends StatementListener {
 				if (aboxModel.contains(stmt)) return true;
 			}
 			
+			return false;
+		} catch (Exception e) {
+			log.debug("exception in method entailedType: " + e.getMessage());
 			return false;
 		} finally {
 			aboxModel.leaveCriticalSection();