我3月底办理EAD/AP combo卡的renew，至今没有动静。前几天发现关于I131怪怪的，大家请看下面：
On April 12, 2013, your Alien Registration Number was changed relating to your I131, APPLICATION FOR USCIS TRAVEL DOCUMENT. Please check our website at www.uscis.gov for further updates on your case. Please wait until the end of normal processing time before calling customer service at 1-800-375-5283 for live assistance.
1）这个大家遇到过吗？
2) 为什么会改变Alien Registration Number
谢谢大家！