Remove IspCP

[theprincy]

I have to remove an installation of ispcp busted and reinstall everything from the beginning but when I unistall this error


Remove user data? [no]: y
groupdel: impossibile rimuovere il gruppo principale dell'utente.

Can not remove group 'mail'!!!

Can not obtain user list!!!

Can not obtain sql user list!!!

Can't use string ("") as an ARRAY ref while "strict refs" in use at ispcp-uninstall line 168, <STDIN> line 2.
dalessio3:/var/www/ispcp/engine/setup#

how can I solve?