Pjiang and other daxia: Using AP and continue with H1B

I plan to use AP back to America in January.At port of entry my lawyer let me show I-485 receipt notice and H-1B approval notice along with AP. then He said I will be in dual status of both I-485 pending and H-1B. Is that ture?
Is there any body show H1B approval notice to CBP then got H1B receipt notice number on your new prolee I-94?

He provided the souce from USCIS:
http://www.uscis.gov/files/pressrelease/HandLFinalRule110107.pdf