Just Returned
I just returned from India via Mumbai on the 25 . My visa which was on my old passport had expired and so had my passport. My new passport did not have any stamp on it .
When you leave US :
1. Surrended your I-94 even if its date has expired as you are now under AOS status .
2. While checking in delta agents had checked my passport for visa and I had do some explanation that I don't need one and showed them original AP doc , EAD card and 485 rcpt. They may not be aware of these so talk confidently to sound that you are talking sense. Also they troubled me for transit visa in Paris . They too were not sure about this and wasted 45 mins in jjust calling around etc . I had taken a print out of the reply I got from French consulate in DC that said AP is good enough and you don't need transit visa. This is required only if you leave the airport .
3. When you land in Mumbai no doc is required. On your return as my PP did not have any visa stamp the delta agent asked for GC . I told them that I was returning on AP which they saw and did not bother at all. Keep some photocopies of AP as airline might keep one . Next at Immigration in mumbai also I had to show AP but She did not want a copy as I told that I had given one to airline .
4. In Paris I just showed AP original and boarded with no problem . When In US at JFK I had to go for secondary inspection to verify case by INS. He stamped AP doc , I-94 for a year from the date I landed although my AP was expiring in 2 weeks .
I was told that sometimes they question about employment etc so I carris paystubs , employment verification letter , 485 rcpt, EAD card along .
Hope this helps.