H1b transfer appoved and help needed in traveling

[guestusa]

FYI:

H1b transfer case:
ND Oct 5,2002
AD Dec 30,2002

I had my H1b visa stamped back in July, 2002,
I-94 vaild to April 30, 2003 with old employer A, new employer B filed the H1b transfer in Oct, 2002, got approval in Dec 30, 2002, valid from Oct,2002 up to Oct, 2005.

My question is May I travel without AP to China and then back to US with my old H1b stamped visa and new H1b transfer approval notice, or I have to have my passport re-stamped ?

Heard of sort of visa revalidation , dont know what it actually means.

Sorry for the naive question, thanks a lot.