Thanks, but still not quite clear.

"Between Receipt date and Approval date: A and/or B.", which one to choose exactly, A or B?

...H1B transfer from A to B with Receipt Notice date 1/3/2011, Approval Notice date 3/3/2011...

So,for question 1, I belonged to A till 3/3, the Approval Notice date? And there will be a gap (between 3/3 and 4/1) of unemployment for me? Is this gap serious to me and my employer differently? If it is serious, I'd better claim my employment with B was started on 3/3, am I right? Please help. I am sending out the RFE.

(Whether a H-1B holder get underpaid or unpaid leave, is not a concern of USCIS, but DOL's. I just read some material yesterday night about the subject. But I may be wrong)