When trying to delete a folder (Action flap->Edit->Delete folder), the question reads: "Do you really want to delete adress book folder 'nome(I18N_ARGUMENT_MISSING)' and all its sub-folders?" The (I8N_ARGUMENT_MISSING) looks misplaced.
Version 4:4.5~20100820.1165966-1maemo1.1167016
Cleverly done in version 4:4.5~20101013.1185418-1maemo1.1185177 .