Invalid SQL: alter table user
add vbchat_pref_font_face varchar(255) not null default '',
add vbchat_pref_font_color varchar(255) not null default '',
add vbchat_pref_user_ignore text not null default '';
mysql error: Duplicate column name 'vbchat_pref_font_face'
Well it seems you already had the edits done, did you have a previous installation of vBChat, if so, what version?