diff --git a/pom.xml b/pom.xml
index 412e4529f38c795791e0c818801feaca5f2774b2..eaa346f266287c043e0b45d5952ab599a1031d75 100644
--- a/pom.xml
+++ b/pom.xml
@@ -87,16 +87,18 @@
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-project-info-reports-plugin</artifactId>
 				<version>2.4</version>
-				<configuration>
-
-				</configuration>
+				<configuration></configuration>
 			</plugin>
 			<plugin>
 				<groupId>org.apache.maven.plugins</groupId>
 				<artifactId>maven-javadoc-plugin</artifactId>
-				<configuration>
-
-				</configuration>
+				<configuration></configuration>
+			</plugin>
+			<plugin>
+				<groupId>org.codehaus.mojo</groupId>
+				<artifactId>findbugs-maven-plugin</artifactId>
+				<version>2.5.2</version>
+				<configuration></configuration>
 			</plugin>
 		</plugins>
 	</reporting>
diff --git a/src/main/java/de/thm/arsnova/dao/CouchDBDao.java b/src/main/java/de/thm/arsnova/dao/CouchDBDao.java
index 812133c002db03bc090c71a0acada1d1a09129db..e72feaacb83365c563099013f9e9cdd934a27ed2 100644
--- a/src/main/java/de/thm/arsnova/dao/CouchDBDao.java
+++ b/src/main/java/de/thm/arsnova/dao/CouchDBDao.java
@@ -109,7 +109,7 @@ public class CouchDBDao implements IDatabaseDao {
 	 */
 	@Override
 	public void cleanFeedbackVotes(int cleanupFeedbackDelay) {
-		final long timelimitInMillis = 60000 * cleanupFeedbackDelay;
+		final long timelimitInMillis = 60000 * (long) cleanupFeedbackDelay;
 		final long maxAllowedTimeInMillis = System.currentTimeMillis() - timelimitInMillis;
 		
 		Map<String, Set<String>> affectedUsers = new HashMap<String, Set<String>>();
@@ -537,7 +537,7 @@ public class CouchDBDao implements IDatabaseDao {
 			
 			JSONObject json = JSONObject.fromObject(loggedIn);
 			Document doc = new Document(json);
-			if (doc.getId() == "") {
+			if (doc.getId().isEmpty()) {
 				// If this is a new user without a logged_in document, we have to remove the following
 				// pre-filled fields. Otherwise, CouchDB will take these empty fields as genuine
 				// identifiers, and will throw errors afterwards.
diff --git a/src/main/java/de/thm/arsnova/entities/User.java b/src/main/java/de/thm/arsnova/entities/User.java
index 75e5691f81f52565ae281316bea7972556a22e37..adc8c14507daa5d9e0e0cd1e7a0de22b5891ae62 100644
--- a/src/main/java/de/thm/arsnova/entities/User.java
+++ b/src/main/java/de/thm/arsnova/entities/User.java
@@ -70,6 +70,7 @@ public class User implements Serializable {
 	
 	@Override
 	public boolean equals(Object obj) {
+		if (obj == null || ! obj.getClass().equals(this.getClass())) return false;
 		User other = (User) obj;
 		return this.username.equals(other.username) && this.type.equals(other.type);
 	}
diff --git a/src/site/site.xml b/src/site/site.xml
index 0ace67ef2b2e91d8798eaee3065c4247314bd927..aed7bfb614bc41d362dd51fd12e917f5a204b781 100644
--- a/src/site/site.xml
+++ b/src/site/site.xml
@@ -50,8 +50,8 @@
 			<item name="The Team" href="team-list.html" />
 		</menu>
 		<menu name="Documentation">
-			<item name="Dependencies" href="dependencies.html" />
 			<item name="Installation" href="installation.html" />
+			<item name="Dependencies" href="dependencies.html" />
 			<item name="API Docs" href="apidocs/index.html" />
 		</menu>
 		<menu name="Further Information">