4t60e first gear problems

[Mitch DOHC]

sometimes, actually it has only done it twice so far, when i come to a stop my car acts like it is in neutral... if change the shifter position and put it back it works fine..... i was just wondering if any one else has had this problem and if so what caused it.... and also how do i change my age in my profile for some reason it says i was born in 1905 witch makes me 101.... i am 25...