I got my passport stamped for GC and recently made a trip outside USA. At the port of entry my passport was scanned and the officer let me in without any questions. He only asked my Driver license for verification. Later I came to know from one of my friend (who is also GC holder and waiting for actual card) that his passport was stamped indicating his entry into USA. My passport was not stamped. Does this create any problem in future. Gurus please clarify.