Mail Aliases not backed up in "Backup Virtual Servers"

Hello:

I am working on transferring to a new server - CentOS6 from CentOS5 - and using the "Backup Virtual Servers" function. All data seems to be transferring perfectly. However, there are some email issues. All users are there, but they are not "active". And, Mail Aliases have not transferred. I have "Backup All Features" checked and also everything checked in "Virtualmin settings to also backup".

Why are email aliases not moving over?

Thanks, Bill