Not sure if I am bringing up some bad vibes here but I was using CBMS for a couple years even though it was a total hack. I have now cleaned it up and released it as madBMS.

Here are some of the new features I have added if you ever used CBMS:

Paypal support
encrypted passwords in the database
signup.php WORKS!!!
added email notification when someone submits signup.php
Invoices are now sent as HTML and include the Paypal button. Clients that don't accept HTML mail will see the old message to login.
Added "Mail Users" page that lets the administrator send an email message to everybody

Let me know what you think I am actively supporting it.