Did you not get an exit stamp from the us / did not turn in departure card ?
 

I had this problem myself and after a couple of hours at the US embassy in Panama I got this piece of paper:

http://www.peterkongsbak.dk/album/US.jpg

Hope this can help someone.

thx Peter

We found that we had ridden straight past US migration at Laredo & didnt notice until too far to go back, so we thought.

We found this info on the US website & had to write to the US embassy in the UK (our origin) but so far have heard nothing.

If anyone else has tried this process, any ideas on how to chase or what the timescales may be or how one can check if it has been processed ?

Cheers
Scouse

US not as organised as you think
 

My wife didn't give back he paper one time she went to the States as she was told not to hand it in if she thought she might go back before it expired. When she went back it had already expired and the guy at the border asked her what had happened to it. She said she had handed it in at the border when she left several months before. His reply was ok and then proceeded to let her in without a problem.
As you just hand in the paper to the guy who takes your toll at the border or give it to an Airline employee if you leave by plane. I don't think they have the control most people think they have. I would just forget about it and don't worry. If someone asks for it just say you gave it in the last tinme you left.

I maybe wrong but that worked for my wife. She is Mexican but I don't think that makes a differences.

Maybe you are right about the US not being that tight. But if you are the unlucky one that gets caught and the immigration guy is having a bad day, they can deport you!

So better safe that sorry.

I personally know a british guy who couldent get back in bacause of this, so it isnt just free fantasy / conspiracy theory

(-:

Good to hear that you may get lucky though.