How do I add a new storage group with a new information store?

I am running Exchange 2003 Standard.  I have one storage group with one Information Store.  I created a second storage group, and there is no store inside the group.  so i try to add a store and I get the error that This Storage Group already contains the maximum number of stores allowed.  But I don't see how this can be, since there is nothing in the storage group.  This is the first one in that group.