VL 5.1 is three years old now. Not many folks are running it at this point. The software repository is gone and it is effectively completely unsupported at this point. It may be awfully hard for you to get an answer. Even worse, VL 5.1 has lots of unpatched security vulnerabilities and new security updates are NOT being provided anymore.
I honestly think it's time for an upgrade. If you're a KDE sort of person then go with VL SOHO 5.9.1.