Samsung galaxy SGH-I777 ATT- 1/2 yrs old. Drops calls as I am talking. There is no rhyme to reason and it does not do it all the time. as Im talking I've noticed sometimes the phone will be black from being dim and then start flashing a couple times then drop the call. sometimes I can call back and it is fine other times it will not let stay connected. I took my phone in and had it reset as new phone and it still does it. I am sure I am not hitting the off button and everyone I take it to says they run tests and its not showing anything. I love the phone other than this issue!