Can't process own output

[jidanni]

For curiosity's sake, I decided to do
load_string($vcard->as_string);

Input:

BEGIN:VCARD
VERSION:3.0
FN:
N:;;;;
TEL;TYPE=WORK:02-25005591
ORG:中國廣播公司節目部
END:VCARD

First run becomes:

BEGIN:VCARD
VERSION:3.0
TEL;TYPE=work:02-25005591
END:VCARD

Second run becomes:

Can't call method "family" on an undefined value at /usr/share/perl5/vCard/AddressBook.pm line 208.