diff --git a/share/etc/oned.conf b/share/etc/oned.conf
index 81ab5670cf..68902b2916 100644
--- a/share/etc/oned.conf
+++ b/share/etc/oned.conf
@@ -48,7 +48,7 @@ DB = [ backend = "sqlite" ]
 #        passwd  = "oneadmin",
 #        db_name = "opennebula" ]
 
-VNC_BASE_PORT = 5000
+VNC_BASE_PORT = 5900
 
 DEBUG_LEVEL=3
 
diff --git a/src/cloud/common/CloudServer.rb b/src/cloud/common/CloudServer.rb
index 157da9366c..a957923f27 100755
--- a/src/cloud/common/CloudServer.rb
+++ b/src/cloud/common/CloudServer.rb
@@ -44,6 +44,10 @@ class CloudServer
 
         @config = Configuration.new(config_file)
 
+        if @config[:vm_type] == nil
+            raise "No VM_TYPE defined."
+        end
+
         @instance_types = Hash.new
 
         if @config[:vm_type].kind_of?(Array)
@@ -56,8 +60,9 @@ class CloudServer
 
         # --- Start an OpenNebula Session ---
 
-        @one_client = Client.new()
+        @one_client = Client.new(nil,@config[:one_xmlrpc])
         @user_pool  = UserPool.new(@one_client)
+
         @img_repo = OpenNebula::ImageRepository.new
     end
 
@@ -123,7 +128,7 @@ class CloudServer
         rc = @img_repo.create(image, template)
 
         file[:tempfile].unlink
-        
+
         if OpenNebula.is_error?(rc)
            return rc
         end
@@ -133,8 +138,8 @@ class CloudServer
 
     # Finds out if a port is available on ip
     # ip:: _String_ IP address where the port to check is
-    # port:: _String_ port to find out whether is open 
-    # [return] _Boolean_ Newly created image object    
+    # port:: _String_ port to find out whether is open
+    # [return] _Boolean_ Newly created image object
     def self.is_port_open?(ip, port)
       begin
         Timeout::timeout(2) do
diff --git a/src/vmm/XenDriver.cc b/src/vmm/XenDriver.cc
index 4866bd583e..53894ffd8d 100644
--- a/src/vmm/XenDriver.cc
+++ b/src/vmm/XenDriver.cc
@@ -320,7 +320,7 @@ int XenDriver::deployment_description(
 
         mac    = nic->vector_value("MAC");
         bridge = nic->vector_value("BRIDGE");
-        
+
         if( !mac.empty() )
         {
             file << "mac=" << mac;
@@ -367,7 +367,17 @@ int XenDriver::deployment_description(
 
                 if ( !port.empty() )
                 {
-                    file << ",vncdisplay=" << port;
+                    istringstream iss(port);
+                    int           display;
+
+                    iss >> display;
+
+                    if ( iss.fail() || display < 5900 )
+                    {
+                        goto error_vncdisplay;
+                    }
+
+                    file << ",vncdisplay=" << display - 5900;
                 }
 
                 if ( !passwd.empty() )
@@ -441,4 +451,11 @@ error_disk:
     vm->log("VMM", Log::ERROR, "Wrong target value in DISK.");
     file.close();
     return -1;
+
+error_vncdisplay:
+    vm->log("VMM", Log::ERROR,
+            "Could not generate a valid xen vncdisplay number, "
+            "vnc port number must be equal or above 5900.");
+    file.close();
+    return -1;
 }