Description of problem:
libvirt (like virt-manager) is fully translated to Bulgarian, but the
translation is not currently present.
Version-Release number of selected component (if applicable):
Reference - bug #238369
The latest version of libvirt didn't update the set of .po files,
I will do this in the next release, this will probably come as
an update to Fedora 7,
Your bg.po is included in libvirt-0.2.3 , which has been pushed to
FC6 and F7 testing updates.
and thank you for doing the localization !