commit 061668208fa6cd8f45cf66dd921a56386de3f3b5
Author: Cole Robinson <crobinso@redhat.com>
Date:   Mon Aug 29 13:12:32 2011 -0400

    VirtualDeviceAddress: Only clear XML if not building from scratch

diff --git a/virtinst/VirtualDevice.py b/virtinst/VirtualDevice.py
index 386eb00..869d50e 100644
--- a/virtinst/VirtualDevice.py
+++ b/virtinst/VirtualDevice.py
@@ -170,7 +170,8 @@ class VirtualDeviceAddress(XMLBuilderDomain):
         self._unit = None
         self._port = None
 
-        self._remove_child_xpath("./address")
+        if self._is_parse():
+            self._remove_child_xpath("./address")
 
     def _get_type(self):
         return self._type