Moon sign discepancy?

Hi i have a discrepancy with my moon sign. I was born on 0ct. 30 1986 at 6:36 am in manhattan NY. one site, tarot.com, says i'm a virgo moon sign and another , astro-software.com/cgi-bin/astro/natal , says i'm a libra moon sign - why is there a discrepancy in the first place ? and whats my real moon sign ?