First time travel to US with new employer's petition and old employer's visa.

[saintsaint]

Hi,

I was working for Company A from which my H1B was processed, I haven't traveled to US not even once and my H1B Petition as well as visa is getting expired in December end,2013.

Now a new employer[Company B] has transferred the petition and its approved.

My queries are,

1. Can I travel to US with new employer's[Company B] petition and old employer's [Company A] visa stamping. OR Should I get new employer's stamping?

2. Will there be any problem at POE?

Thanks