shared iCloud account with iMessage conflict

My wife and I have shared the same icloud/me.com account on both our computers and iPhone and there has been no problems for years. Recently, when iMessage is enabled on both our phones she will receive text's that were meant for me and vice versa. How do I resolve this without completely removing the original iCloud account and creating a new one. I've taken steps to create a new iCloud account but it seems that the iPhone only wants one "parent" account and I'm concerned that I'll lose what we've had with the shared account. Is there anyway to keep the secondary iCloud account and enable it for messaging? Any ideas would be helpful, thanks.

Adam