Cannot add email address as an alias

I erroneously set up a second Live account with another email address.  Once I figured out I could simply add that email as an alias to my original Live account, I deleted the second account.  The system is not letting add the second account email as an alias to the original account.  It keeps saying that the alias email address is already taken, but it's not.  It's my non-Microsoft email account.  I deleted the Live account that was using it so it should be available to me.  Both email address are non-Microsoft accounts.  Is there some kind of a waiting period to re-use my own email addresses? Why?  I'm part of a team that uses calendar sharing via Live.  If I cant get this working soon, it will be a significant impediment to my productivity.