diff -Nuar virt-manager-0.5.3.orig/src/virtManager/addhardware.py virt-manager-0.5.3/src/virtManager/addhardware.py
--- virt-manager-0.5.3.orig/src/virtManager/addhardware.py	2008-04-09 11:04:13.000000000 -0600
+++ virt-manager-0.5.3/src/virtManager/addhardware.py	2008-04-09 11:06:27.000000000 -0600
@@ -840,6 +840,8 @@
                 model.append(["xvd", 26, virtinst.VirtualDisk.DEVICE_DISK, gtk.STOCK_HARDDISK, "Virtual disk"])
             #model.append(["usb", virtinst.VirtualDisk.DEVICE_DISK, gtk.STOCK_HARDDISK, "USB disk"])
         else:
+            # add read-only option to prevent libvirt exceptions when adding a cdrom as read/write
+            model.append(["xvd", 26, virtinst.VirtualDisk.DEVICE_CDROM, gtk.STOCK_CDROM, "Virtual disk (read-only)"])
             model.append(["xvd", 26, virtinst.VirtualDisk.DEVICE_DISK, gtk.STOCK_HARDDISK, "Virtual disk"])
 
     def populate_input_model(self, model):