diff --git a/gns3server/modules/dynamips/__init__.py b/gns3server/modules/dynamips/__init__.py
index ed538f23..16bc67c6 100644
--- a/gns3server/modules/dynamips/__init__.py
+++ b/gns3server/modules/dynamips/__init__.py
@@ -494,12 +494,12 @@ class Dynamips(BaseManager):
             yield from vm.set_sparsemem(False)
 
         # update the configs if needed
-        yield from self.create_vm_configs(vm, settings)
+        yield from self.set_vm_configs(vm, settings)
 
     @asyncio.coroutine
-    def create_vm_configs(self, vm, settings):
+    def set_vm_configs(self, vm, settings):
         """
-        Creates VM configs from pushed content.
+        Set VM configs from pushed content or existing config files.
 
         :param vm: VM instance
         :param settings: VM settings
@@ -514,16 +514,18 @@ class Dynamips(BaseManager):
             startup_config_path = self._create_config(vm, startup_config_content, default_startup_config_path)
             yield from vm.set_configs(startup_config_path)
         else:
-            startup_config_path = settings.get("startup_config", "")
-            yield from vm.set_configs(startup_config_path)
+            startup_config_path = settings.get("startup_config")
+            if startup_config_path:
+                yield from vm.set_configs(startup_config_path)
 
         private_config_content = settings.get("private_config_content")
         if private_config_content:
             private_config_path = self._create_config(vm, private_config_content, default_private_config_path)
             yield from vm.set_configs(vm.startup_config, private_config_path)
         else:
-            private_config_path = settings.get("private_config", "")
-            yield from vm.set_configs(vm.startup_config, private_config_path)
+            private_config_path = settings.get("private_config")
+            if private_config_path:
+                yield from vm.set_configs(vm.startup_config, private_config_path)
 
     def _create_config(self, vm, content, path):
         """
diff --git a/gns3server/modules/dynamips/hypervisor.py b/gns3server/modules/dynamips/hypervisor.py
index 5a620357..ce1b4ade 100644
--- a/gns3server/modules/dynamips/hypervisor.py
+++ b/gns3server/modules/dynamips/hypervisor.py
@@ -138,9 +138,9 @@ class Hypervisor(DynamipsHypervisor):
             try:
                 yield from asyncio.wait_for(self._process.wait(), timeout=3)
             except asyncio.TimeoutError:
-                self._process.kill()
                 if self._process.returncode is None:
-                    log.warn("Dynamips process {} is still running".format(self._process.pid))
+                    log.warn("Dynamips process {} is still running... killing it".format(self._process.pid))
+                    self._process.kill()
 
         if self._stdout_file and os.access(self._stdout_file, os.W_OK):
             try:
diff --git a/gns3server/modules/dynamips/nodes/router.py b/gns3server/modules/dynamips/nodes/router.py
index 98d9384f..03a8f60c 100644
--- a/gns3server/modules/dynamips/nodes/router.py
+++ b/gns3server/modules/dynamips/nodes/router.py
@@ -1249,6 +1249,8 @@ class Router(BaseVM):
                                                                                                                   port_number=port_number))
 
         nio = adapter.get_nio(port_number)
+        if nio is None:
+            return
         if isinstance(nio, NIOUDP):
             self.manager.port_manager.release_udp_port(nio.lport)
         adapter.remove_nio(port_number)
diff --git a/gns3server/modules/iou/iou_vm.py b/gns3server/modules/iou/iou_vm.py
index 059db000..299a9258 100644
--- a/gns3server/modules/iou/iou_vm.py
+++ b/gns3server/modules/iou/iou_vm.py
@@ -488,9 +488,10 @@ class IOUVM(BaseVM):
                 try:
                     yield from gns3server.utils.asyncio.wait_for_process_termination(self._iou_process, timeout=3)
                 except asyncio.TimeoutError:
-                    self._iou_process.kill()
                     if self._iou_process.returncode is None:
-                        log.warn("IOU process {} is still running".format(self._iou_process.pid))
+                        log.warn("IOU process {} is still running... killing it".format(self._iou_process.pid))
+                        self._iou_process.kill()
+
             self._iou_process = None
 
             if self._iouyap_process is not None:
@@ -498,11 +499,11 @@ class IOUVM(BaseVM):
                 try:
                     yield from gns3server.utils.asyncio.wait_for_process_termination(self._iouyap_process, timeout=3)
                 except asyncio.TimeoutError:
-                    self._iouyap_process.kill()
                     if self._iouyap_process.returncode is None:
-                        log.warn("IOUYAP process {} is still running".format(self._iouyap_process.pid))
-            self._iouyap_process = None
+                        log.warn("IOUYAP process {} is still running... killing it".format(self._iouyap_process.pid))
+                        self._iouyap_process.kill()
 
+            self._iouyap_process = None
             self._started = False
 
     def _terminate_process_iouyap(self):
diff --git a/gns3server/modules/vpcs/vpcs_vm.py b/gns3server/modules/vpcs/vpcs_vm.py
index 56c89bd1..dad5e87c 100644
--- a/gns3server/modules/vpcs/vpcs_vm.py
+++ b/gns3server/modules/vpcs/vpcs_vm.py
@@ -245,9 +245,9 @@ class VPCSVM(BaseVM):
             try:
                 yield from asyncio.wait_for(self._process.wait(), timeout=3)
             except asyncio.TimeoutError:
-                self._process.kill()
                 if self._process.returncode is None:
-                    log.warn("VPCS process {} is still running".format(self._process.pid))
+                    log.warn("VPCS process {} is still running... killing it".format(self._process.pid))
+                    self._process.kill()
 
         self._process = None
         self._started = False