[libvirt] problem: deleting a guest

I defined a new guest using the virt-manager GUI ... everything fine so far. I then decided that my definition was not correct (or I could be done with that guest) and could not find a way to delete the guest. OK, quit virt-manager, delete the configuration and disk-image files for the guest, restart libvirtd, and then start virt-manager again. The guest definition (according to virt-manager) was still there. I finnaly got rid of the definition by re-booting the system. THIS IS NOT SATISFACTORY! IMHO, I should be able to: 1. Define a new guest. 2. Delete the definition of a new guest but not the related configuration and disk-image files. 3. Delete the guest definition and the related configuration and disk image files but NOT and CD/DVD image files external to /var/lib/libvirt/images. 4. Import new guests which were created as clones, copied from another host, or convert created from something like VMware. Not it is certainly possible (or even likely) that I h\just do not understand how to do things yet. Or, this could be a bug. Or, this could be a lack of capabilities. Help appreciated in pointing me in the right direction. I will bugzilla where appropriate. Gene