diff --git a/server/src/com/cloud/user/AccountManagerImpl.java b/server/src/com/cloud/user/AccountManagerImpl.java
index f584aa1aef1..4a8a4c4c436 100755
--- a/server/src/com/cloud/user/AccountManagerImpl.java
+++ b/server/src/com/cloud/user/AccountManagerImpl.java
@@ -1421,32 +1421,42 @@ public class AccountManagerImpl implements AccountManager, AccountService, Manag
 
         checkAccess(UserContext.current().getCaller(), account);
 
-        if (firstName == null) {
-            firstName = user.getFirstname();
+        if (firstName != null) {
+            user.setFirstname(firstName);
         }
-        if (lastName == null) {
-            lastName = user.getLastname();
+        if (lastName != null) {
+            user.setLastname(lastName);
         }
-        if (userName == null) {
-            userName = user.getUsername();
+        if (userName != null) {
+            //don't allow to have same user names in the same domain
+            List<UserVO> duplicatedUsers = _userDao.findUsersLike(userName);
+            for (UserVO duplicatedUser : duplicatedUsers) {
+                if (duplicatedUser.getId() != user.getId()) {
+                    Account duplicatedUserAccount = _accountDao.findById(duplicatedUser.getAccountId());
+                    if (duplicatedUserAccount.getDomainId() == account.getDomainId()) {
+                        throw new InvalidParameterValueException("User with name " + userName + " already exists in domain " + duplicatedUserAccount.getDomainId());
+                    }
+                }
+            }
+            
+            user.setUsername(userName);
         }
-        if (password == null) {
-            password = user.getPassword();
+        if (password != null) {
+            user.setPassword(password);
         }
-        if (email == null) {
-            email = user.getEmail();
+        if (email != null) {
+            user.setEmail(email);
         }
-        if (timeZone == null) {
-            timeZone = user.getTimezone();
+        if (timeZone != null) {
+            user.setTimezone(timeZone);
         }
-        if (apiKey == null) {
-            apiKey = user.getApiKey();
+        if (apiKey != null) {
+            user.setApiKey(apiKey);
         }
-        if (secretKey == null) {
-            secretKey = user.getSecretKey();
+        if (secretKey != null) {
+            user.setSecretKey(secretKey);
         }
 
-        Long accountId = user.getAccountId();
 
         if (s_logger.isDebugEnabled()) {
             s_logger.debug("updating user with id: " + id);
@@ -1465,8 +1475,8 @@ public class AccountManagerImpl implements AccountManager, AccountService, Manag
                     }
                 }
             }
-
-            _userDao.update(id, userName, password, firstName, lastName, email, accountId, timeZone, apiKey, secretKey);
+            
+            _userDao.update(id, user);
         } catch (Throwable th) {
             s_logger.error("error updating user", th);
             throw new CloudRuntimeException("Unable to update user " + id);
diff --git a/server/src/com/cloud/user/dao/UserDao.java b/server/src/com/cloud/user/dao/UserDao.java
index 4ee3a12a85b..1ec7eb21469 100644
--- a/server/src/com/cloud/user/dao/UserDao.java
+++ b/server/src/com/cloud/user/dao/UserDao.java
@@ -33,21 +33,6 @@ public interface UserDao extends GenericDao<UserVO, Long>{
 	UserVO getUser(long userId);
 	List<UserVO> findUsersLike(String username);
 	
-	/**
-	 * updates a user with the new username, password, firstname, lastname, email,accountId, timezone
-	 * @param id
-	 * @param username
-	 * @param password
-	 * @param firstname
-	 * @param lastname
-	 * @param email
-	 * @param accountId
-	 * @param timezone
-	 * @param apikey
-	 * @param secretkey
-	 */
-	void update(long id, String username, String password, String firstname, String lastname, String email, Long accountId, String timezone, String apiKey, String secretKey);
-	
 	List<UserVO> listByAccount(long accountId);
 
 	/**
diff --git a/server/src/com/cloud/user/dao/UserDaoImpl.java b/server/src/com/cloud/user/dao/UserDaoImpl.java
index 9fba2b19d9a..7af8ec7d9b9 100644
--- a/server/src/com/cloud/user/dao/UserDaoImpl.java
+++ b/server/src/com/cloud/user/dao/UserDaoImpl.java
@@ -26,7 +26,6 @@ import com.cloud.user.UserVO;
 import com.cloud.utils.db.GenericDaoBase;
 import com.cloud.utils.db.SearchBuilder;
 import com.cloud.utils.db.SearchCriteria;
-import com.cloud.utils.exception.CloudRuntimeException;
 
 /**
  * Implementation of the UserDao
@@ -116,29 +115,6 @@ public class UserDaoImpl extends GenericDaoBase<UserVO, Long> implements UserDao
         SearchCriteria<UserVO> sc = SecretKeySearch.create();
         sc.setParameters("secretKey", secretKey);
         return findOneBy(sc);
-    }
-    
-    @Override
-    public void update(long id, String username, String password, String firstname, String lastname, String email, Long accountId, String timezone, String apiKey, String secretKey)
-    {
-        UserVO dbUser = getUser(username);
-        if ((dbUser == null) || (dbUser.getId() == id)) {
-            UserVO ub = createForUpdate();
-            ub.setUsername(username);
-            ub.setPassword(password);
-            ub.setFirstname(firstname);
-            ub.setLastname(lastname);
-            ub.setEmail(email);
-            ub.setAccountId(accountId);
-            ub.setTimezone(timezone);
-            ub.setApiKey(apiKey);
-            ub.setSecretKey(secretKey);
-            update(id, ub);
-        }
-        else
-        {
-            throw new CloudRuntimeException("unable to update user -- a user with that name exists");
-        }
     }
 
 	@Override