H1B stamping in the passport after change of employer

Hello Saurabh,

I held an H1b visa with employer A until May 2013. The visa validity period is September 2014. My I-94 is also valid until October 2014. Due to change in employment conditions, I filed a COS in May from H1b to L2. The COS is pending till date. I found a new employer B who is willing to sponsor my H1b visa. The visa is however being filed under consular notification and not as a COS as my previous COS is still underway. I was informed by the attorney that I can travel to Mexico and reenter the US without the new visa stamp in my passport and by just producing the new I-797 petition for a new I-94 issuance since my H1b visa from the previous employer is still valid . Here are my questions:

	Do you think it is safe to follow this route. Are there any chances that I might be denied re-entry upon my return from Mexico?

	I have an approved I-140 petition from my previous employer. Do I need to apply for an advanced parole to leave the US and re-enter? Note that I have not yet applied for I-485 as my visa date is not current.

Your responses are highly appreciated.

Thanks in advance for your help.