diff --git a/gns3server/modules/iou/__init__.py b/gns3server/modules/iou/__init__.py
index fad5eb91..2c094b75 100644
--- a/gns3server/modules/iou/__init__.py
+++ b/gns3server/modules/iou/__init__.py
@@ -253,7 +253,7 @@ class IOU(IModule):
             self._working_dir = new_working_dir
             for iou_id in self._iou_instances:
                 iou_instance = self._iou_instances[iou_id]
-                iou_instance.working_dir = self._working_dir
+                iou_instance.working_dir = os.path.join(self._working_dir, "iou", "device-{}".format(iou_instance.id))
 
         if "console_start_port_range" in request and "console_end_port_range" in request:
             self._console_start_port_range = request["console_start_port_range"]
diff --git a/gns3server/modules/iou/iou_device.py b/gns3server/modules/iou/iou_device.py
index 09ca54c6..6c5b8704 100644
--- a/gns3server/modules/iou/iou_device.py
+++ b/gns3server/modules/iou/iou_device.py
@@ -550,7 +550,7 @@ class IOUDevice(object):
 
         if not self.is_running():
 
-            if not os.path.isfile(self._path):
+            if not os.path.isfile(self._path) or not os.path.exists(self._path):
                 raise IOUError("IOU image '{}' is not accessible".format(self._path))
 
             try:
diff --git a/gns3server/modules/vpcs/__init__.py b/gns3server/modules/vpcs/__init__.py
index c7493d4d..230f97f1 100644
--- a/gns3server/modules/vpcs/__init__.py
+++ b/gns3server/modules/vpcs/__init__.py
@@ -189,7 +189,7 @@ class VPCS(IModule):
             self._working_dir = new_working_dir
             for vpcs_id in self._vpcs_instances:
                 vpcs_instance = self._vpcs_instances[vpcs_id]
-                vpcs_instance.working_dir = self._working_dir
+                vpcs_instance.working_dir = os.path.join(self._working_dir, "vpcs", "pc-{}".format(vpcs_instance.id))
 
         if "console_start_port_range" in request and "console_end_port_range" in request:
             self._console_start_port_range = request["console_start_port_range"]
diff --git a/gns3server/version.py b/gns3server/version.py
index c15d4ef7..d83ac325 100644
--- a/gns3server/version.py
+++ b/gns3server/version.py
@@ -23,5 +23,5 @@
 # or negative for a release candidate or beta (after the base version
 # number has been incremented)
 
-__version__ = "1.0a7.dev3"
+__version__ = "1.0a7"
 __version_info__ = (1, 0, 0, -99)