Client User Management - Mulitple Projects

Client User Management - Mulitple Projects

Hello...
I have been struggling to determine how to handle our users and their accounts in Zoho Projects.  I will try to best describe our situation and look forward to your response:
We have multiple Projects that are setup with different staff members managing each.  We also have our clients who we like to interact with through forums, document sharing and our wikis.  However, what we are finding is that once we add a client user to a project, that client user cannot be added as a client user to another project that we are managing.

Quick example
John Q is added as a client user for Project ABC - John Q's account on zoho is tied to johnq@email.com
We want to add John Q as a client user for Project XYZ - so under that project we use the add client function and it prompts for email, we type in johnq@email.com and it displays a message that this user already has an account and cannot be added to Project XYZ.
Even as an administrator looking at all users in User Management, I can see John Q and his account under Project ABC, but when I try to edit his account Project ABC shows as his working project, but no of our other projects are loaded under Available Projects.

In one instance to get a client user added to multiple projects we had to add the user as a Company User and remove him from the client user group.  However, I am trying to keep only staff members in the Company User group and our customers in the client user group.

Any help here would be much appreciated...