Votes from same IP address

My wife and I are both on this site, but under different accounts, but being in the same house, we "share" a single IP address. When voting, it records the IP address and not the user. I voted on a poem, and when she went to vote, it said she already voted, and therefor could not give her vote.

This can easily be rectified, and it's just my thought that the voting system should be by unique identifier of username, rather IP.

Just my 2 cents (as a website developer myself)

My bro is also on this site and he voted on like 5 of my poems. I received a pm saying i had created a dummy account or myself so i could be voting on my work just cause we share the same ip address.