My previous H1b visa with university A expired on June 30, 2009, and my current H1b visa with university B is valid from July 20, 2009 until June 30 2011. I went to China to visit my parents on July 4, and came back with my AP on July 30. With the current H1b visa, I started to work at university B on August 3, but on last Friday, the payroll office informed me that I need to call the Department of Homeland Security (DHS) to verify some information such as my name, A-number, and/or I-94 number. I guess that the problem is the I-94 number because the number in the I-94 with which I entered US on July 30, 2009 is different from that in the I-94 with my current H1b visa. Now my questions are as follows:
1) What is my latest I-94? The one with my current H1b or the one when I entered US with AP recently?
2) What is my current status? H1b or DOS?
3) Am I legal to work using my current H1b or do I have to use EAD?
Thank you very much for your answer in advance