本人于5月13日收到140通过的 notification email. 但之后一个月也没有收到正式的approval letter.询问HR,HR 说要联系律师。之后一个星期，偶然发现以前收到的140 Receipt 上的HR office 地址是旧地址。告知HR后，两星期前HR called USCIS 更改了地址，但到现在已过两星期了，还是没收到信。与其他同事聊了聊，发现我的140 case status似乎与其他人不同。请教各位，我的140 case status是不是有错误，现在该怎么办。
以下是我的140 notification email 中的部分内容
Application Type: I140 , IMMIGRANT PETITION FOR ALIEN WORKER
Your Case Status: Card/ Document Production
On May 13, 2011 we mailed the document to the address we have on file. You should receive the new document within 30 days. If you do not, or if you move before you get it, call customer service at 1-800-375-5283.
This step applies to applications that result in an applicant receiving a card (such as a "green card") or other document (such as a naturalization certificate, employment authorization document, travel document, or advance parole). Applications will be in this step from the time the order to produce the card/document is given until the card/document is produced and mailed to the applicant. You can expect to receive your card/document within 30 days of the approval of your application.