is labor approval valid which was filed by previous employer

Hi All

I would like to know if the labor filed by previous employer is still valid.

My H1 6 year cap will be over by next april 2014.

I was wtih emplyer A till this May 2013 and moved to employer B. But in Jan 2013 emplyer A filed my labor and its approved in Aug 2013. Since i was not with employer A after May 2013 is my labor valid ??

Even employer B filed my labor in december 2013 but since because of shutdown it got delayed and i was told by attorney that i might not get labor cetified before next april 2014.

Are there going to be any chances of getting I140 if i move to my previous employer. Please let me know at the earliest.