Hi,

I had a J1 Visa for an Internship in the USA from February to April 2012. In April, the company I was working for,
offered me a longer internship so I extended the Visa until end of January 2013. I had to go back to Germany in May and went back mid June. The Council that helped me with the extension, told me there would be no need to go back to the embassy in Germany for that.
All I needed was the DS-2019. This was sent to me with the new dates.

When I wanted to enter the USA in mid June, the US Department at the airport told me, I could not enter the USA because my visa in the passport was not valid, because I only had the DS-2019 with the extended dates, the visa in the passport was not extended.
(it was expired and I was told the approved DS-2019 with the new dates would be enough)
With signing a Waiver I-193 at the airport, they did let me enter the USA.

Now I have to go back to Germany for a short visit. My DS-2019 is valid until Jan 2013 and I have the Waiver.
My question is now, can I come back and enter the USA with that Waiver or do I have to go to the embassy to get the extension
in my passport? And/Or do I have to get a form at the US airport before leaving?

I am also not sure if I have to hand out my I-94 form at the airport before leaving at this time.

I hope you can help me here. Thank you