diff -Nuar virt-manager-0.5.3.orig/src/virtManager/connection.py virt-manager-0.5.3/src/virtManager/connection.py
--- virt-manager-0.5.3.orig/src/virtManager/connection.py	2008-02-20 14:13:33.000000000 -0700
+++ virt-manager-0.5.3/src/virtManager/connection.py	2008-02-20 14:14:31.000000000 -0700
@@ -136,6 +136,20 @@
 
         self.detect_network_devices()
 
+    # A bug in hal prevents us from calling QueryCapability on devices
+    # this is a temporary workaround that can be removed when we get
+    # a newer hald/hald_dbus.c
+    def _query_capability(self, device_interface, str_capability):
+        if device_interface == None:
+            return False
+        if not device_interface.PropertyExists('info.capabilities'):
+            return False
+        cap_set = set(device_interface.GetProperty('info.capabilities'))
+        if str_capability in cap_set:
+            return True
+        return False
+
+
     def detect_network_devices(self):
         try:
             # Get a connection to the SYSTEM bus
@@ -161,7 +175,7 @@
 
     def _device_added(self, path):
         obj = self.bus.get_object("org.freedesktop.Hal", path)
-        if obj.QueryCapability("net"):
+        if self._query_capability(obj,"net"):
             name = obj.GetPropertyString("net.interface")
             mac = obj.GetPropertyString("net.address")
 
diff -Nuar virt-manager-0.5.3.orig/src/virtManager/opticalhelper.py virt-manager-0.5.3/src/virtManager/opticalhelper.py
--- virt-manager-0.5.3.orig/src/virtManager/opticalhelper.py	2008-02-20 14:13:33.000000000 -0700
+++ virt-manager-0.5.3/src/virtManager/opticalhelper.py	2008-02-20 14:14:57.000000000 -0700
@@ -41,6 +41,19 @@
             self.hal_iface = None
             raise
 
+    # A bug in hal prevents us from calling QueryCapability on devices
+    # this is a temporary workaround that can be removed when we get
+    # a newer hald/hald_dbus.c
+    def _query_capability(self, device_interface, str_capability):
+        if device_interface == None:
+            return False
+        if not device_interface.PropertyExists('info.capabilities'):
+            return False
+        cap_set = set(device_interface.GetProperty('info.capabilities'))
+        if str_capability in cap_set:
+            return True
+        return False
+
     def populate_opt_media(self):
         # get a list of optical devices with data discs in, for FV installs
         vollabel = {}
@@ -71,7 +84,7 @@
 
     def _device_added(self, path):
         vol = self.bus.get_object("org.freedesktop.Hal", path)
-        if vol.QueryCapability("volume"):
+        if self._query_capability(vol,"volume"):
             if vol.GetPropertyBoolean("volume.is_disc") and \
                    vol.GetPropertyBoolean("volume.disc.has_data"):
                 devnode = vol.GetProperty("block.device")